[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
This bug was fixed in the package util-linux - 2.27.1-6ubuntu3.9 --- util-linux (2.27.1-6ubuntu3.9) xenial; urgency=medium * d/p/libblkid-nilfs2-add-length-check-before-crc32.patch: Fix misdetection/false-positive of nilfs2 filesystem on device with magic bytes coincidentally on end of device and bad checksum ignored by udev blkid. (LP: #1842437) -- Mauricio Faria de Oliveira Tue, 03 Sep 2019 11:32:50 -0300 ** Changed in: util-linux (Ubuntu Xenial) Status: Fix Committed => Fix Released -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: Fix Released Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
** Tags removed: sts-sponsor-slashd -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: Fix Committed Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
Verification done with xenial-proposed. # dpkg -s libblkid1 | grep -i version Version: 2.27.1-6ubuntu3.9 # apt-cache madison libblkid1 | grep xenial-proposed libblkid1 | 2.27.1-6ubuntu3.9 | http://archive.ubuntu.com/ubuntu xenial-proposed/main amd64 Packages Test steps are described in comment #6. Only one filesystem (ext4) is detected: # udevadm test-builtin blkid /sys/block/$(basename $dev)/$(basename $part) ... ID_FS_UUID=aadbf085-7ce7-43e4-a149-ad11d997b710 ID_FS_UUID_ENC=aadbf085-7ce7-43e4-a149-ad11d997b710 ID_FS_VERSION=1.0 ID_FS_TYPE=ext4 ID_FS_USAGE=filesystem ... # echo $? 0 The verbose log shows nilfs is not detected: # LIBBLKID_DEBUG=all udevadm test-builtin blkid /sys/block/$(basename $dev)/$(basename $part) ... 2177: libblkid: LOWPROBE: [63] nilfs2: 2177: libblkid: LOWPROBE: call probefunc() 2177: libblkid: LOWPROBE: reuse buffer: off=1024 len=1024 pr=0x5598289abc80 2177: libblkid: LOWPROBE: reuse buffer: off=16772608 len=4096 pr=0x5598289abc80 2177: libblkid: LOWPROBE: [64] exfat: ... ** Tags added: verification-done-xenial -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: Fix Committed Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
No problems with the autopkgtest results for this SRU: - nplan xenial/s390x [1] is failing since September 1st - nplan xenial/armhf [2] is failing since May 14th - systemd xenial/amd [3] passed with a re-run [4] (thanks ddstret) cheers, Mauricio [1] https://autopkgtest.ubuntu.com/packages/nplan/xenial/s390x [2] https://autopkgtest.ubuntu.com/packages/nplan/xenial/armhf [3] https://autopkgtest.ubuntu.com/packages/systemd/xenial/amd64 [4] https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-xenial/xenial/amd64/s/systemd/20191010_142631_c890a@/log.gz -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: Fix Committed Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
The reported failures for autopkgtest are unrelated to this change on the probe of the nilfs filesystem. Two are apparently failures in handling test reboot, and another is lack of a kernel module. I'll ask for retries on these, and do a quick check on this module error. Details: --- nplan:armhf autopkgtest [10:35:43]: test process requested reboot with marker config Unexpected error: ... VirtSubproc.Timeout autopkgtest [10:37:09]: ERROR: testbed failure: unexpected eof from the testbed nplan:s390x autopkgtest [10:20:42]: test integration.py: [--- modprobe: FATAL: Module cfg80211 not found in directory /lib/modules/4.4.0-165-generic ... subprocess.CalledProcessError: Command '['modprobe', 'cfg80211']' returned non-zero exit status 1 ... integration.py FAIL non-zero exit status 1 systemd:amd64 sudo: /tmp/autopkgtest-run-wrapper: command not found Exit request sent. : failure: timed out waiting for testbed to reboot autopkgtest [11:39:57]: ERROR: testbed failure: cannot send to testbed: [Errno 32] Broken pipe -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: Fix Committed Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
Hello Mauricio, or anyone else affected, Accepted util-linux into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/util- linux/2.27.1-6ubuntu3.9 in a few hours, and then in the -proposed repository. Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users. If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-xenial to verification-done-xenial. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-xenial. In either case, without details of your testing we will not be able to proceed. Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping! N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days. ** Changed in: util-linux (Ubuntu Xenial) Status: In Progress => Fix Committed -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: Fix Committed Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
[STS-Sponsor] Sponsored in Bionic. Thanks Mauricio for your great work on this bug and the FTBFS situation. - Eric -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
And this debdiff / util-linux on xenial builds fine again! Built on all architectures on PPA [1]. cheers, Mauricio [1] https://launchpad.net/~mfo/+archive/ubuntu/lp1842437 -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
Eric, The fix to xenial livecd-rootfs / launchpad buildd chroot has been rolled out. I just confirmed that /dev/ptmx is OK with a test package build on Launchpad PPA. ... dh_clean # Check /dev/ptmx|pts/ ls -l /dev/ptmx crw-rw-rw- 1 root root 5, 2 Oct 4 08:13 /dev/ptmx ls -l /dev/pts/* c- 1 root root 5, 2 Oct 4 11:25 /dev/pts/ptmx make[1]: Leaving directory '/<>/test-pkg-1.0+devpts1' ... Now testing a build of util-linux, and hopefully we can move forward with the SRU again. cheers, Mauricio -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
Eric, thanks! Really appreciate your help debugging this issue. Per Colin's comment, he mentions on #launchpad-ops (internal) when there are launchpad chroot changes -- so we can confirm it's been updated after the package becomes Fix Released. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
@mfo, I will gladly resume the sponsoring as soon as LP: #1844504 is "Fix Released" and util-linux builds fine. Thanks for your good work on this Mauricio ! -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
The real fix for the openpty() problem on Launchpad xenial buildd is in livecd-rootfs currently in xenial-proposed, and is verified. (LP 1844504 comment 15) Once the Launchpad builders are updated with that, we can proceed with another build attempt, and hopefully move this SRU forward. Thanks to Colin Watson (cjwatson) for quickly fixing livecd-rootfs. cheers, Mauricio -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
LP: #1844504 ** Tags added: ftbfs -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
Workaround of disabling the 4 tests in the 'script' component (which calls openpty() upfront and thus cause the failure) makes the test-suite finish successfully. $ ./tests/run.sh \ --srcdir=/build/util-linux-kzgHhT/util-linux-2.27.1 \ --builddir=/build/util-linux-kzgHhT/util-linux-2.27.1 \ --parallel --nonroot --verbose \ --exclude='script/buffering-race script/options script/race script/replay' ... """ All 166 tests PASSED """ -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
s/this is bug/this is _similar_ to/ -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
Ah, this is bug 1843674, checking for similar fixes. (thanks Matthew Ruffell for pointing it out on IRC.) -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
The problem is reproducible in the sbuild-launchpad-chroot for xenial/amd64, using the source package for util-linux currently in xenial-updates (i.e., no regression from debdiff, as expected since changes/error are unrelated) The minimal command-line for that is: $ /build/util-linux-kzgHhT/util-linux-2.27.1/script -c echo Hallo World /dev/null /build/util-linux-kzgHhT/util- linux-2.27.1/tests/output/script/buffering-race script: openpty failed: No such file or directory Terminated There was a suspicion about the kernel version difference/regression (4.4.0-159 and -161), but that's was not the root cause of the issue. Looking into other areas. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
Eric, thanks for reporting that. I couldn't reproduce the build failure on LXC with apt dist-upgrade on xenial-updates nor xenial-proposed, and it built successfully on PPAs a while ago (for the test packages), so it seems something changed in the PPA builders. I'll investigate this as per our discussion on IRC, and get back to you. Thanks, Mauricio -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
@mfo, Unfortunately the build ftbfs as follow: https://launchpadlibrarian.net/443016838/buildlog_ubuntu-xenial-amd64.util-linux_2.27.1-6ubuntu3.9_BUILDING.txt.gz ... masks: script: openpty failed: No such file or directory Makefile:11211: recipe for target 'check-recursive' failed make[3]: *** [check-recursive] Terminated debian/rules:177: recipe for target 'override_dh_auto_test' failed make[1]: *** [override_dh_auto_test] Terminated debian/rules:54: recipe for target 'build' failed make: *** [build] Terminated E: Caught signal ‘Terminated’: terminating immediately ... Investigation is going to be needed. - Eric -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
Maybe a kernel change between your successful built and my today sponsoring build failure ? -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
The reporter confirmed the boot problem doesn't happen anymore. Moving forward with the SRU. ** Changed in: util-linux (Ubuntu Xenial) Assignee: Guilherme G. Piccoli (gpiccoli) => Mauricio Faria de Oliveira (mfo) ** Tags added: sts -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
** Tags added: sts-sponsor-slashd -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more. [Test Case] * Synthetic test case written for this problem on comment #6. [Regression Potential] * Low. The code is contained in the probe for the nilfs filesystem. * This just makes it be more restrictive about the possibly valid values for a few bytes read from disk (that now need to be within the acceptable range of valid values) so this only decreases false- positives, and cannot increase false-negatives of valid filesystems. [Original Description] The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
Attaching the debdiff with the fix. This is waiting on validation from the reported user that the boot problem does not happen anymore -- but has already been validated on the running system to produce the correct/expected behavior (UUID / other values are printed by 'udevadm test-builtin blkdid'). I'll be out the next week, so this should probably be handled by Guilherme Piccoli during this time. ** Description changed: + [Impact] + + * Users / systemd can fail to mount a filesystem by UUID +(e.g., during boot, triggering emergency shell prompt) +if the magic bytes for the nilfs filesystem are written +to the right place in a partition of another filesystem, +(for whatever reason or coincidence). + + * Note this can happen after the filesystem/mount is working +correctly, so a change of behavior/problem can potentially +be noticed when trying to mount the filesystem again, which +can very well be the next time the system boots. + + * This happens because if udev blkid detects more than one +filesystem, it does not print the UUID env vars required +to create the /dev/disk/by-id symlinks and other things. + + * The fix enhances the check for valid nilfs superblock by +specifically checking a value read from disk to be valid/ +within a value range, which addresses this one occurrence +and prevents a lot more. + + [Test Case] + + * Synthetic test case written for this problem on comment #6. + + [Regression Potential] + + * Low. The code is contained in the probe for the nilfs filesystem. + + * This just makes it be more restrictive about the possibly valid +values for a few bytes read from disk (that now need to be within +the acceptable range of valid values) so this only decreases false- +positives, and cannot increase false-negatives of valid filesystems. + + [Original Description] + The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. ** Patch added: "lp1842437_util-linux.debdiff" https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+attachment/5287043/+files/lp1842437_util-linux.debdiff ** Changed in: util-linux (Ubuntu Xenial) Assignee: Mauricio Faria de Oliveira (mfo) => Guilherme G. Piccoli (gpiccoli) -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: [Impact] * Users / systemd can fail to mount a filesystem by UUID (e.g., during boot, triggering emergency shell prompt) if the magic bytes for the nilfs filesystem are written to the right place in a partition of another filesystem, (for whatever reason or coincidence). * Note this can happen after the filesystem/mount is working correctly, so a change of behavior/problem can potentially be noticed when trying to mount the filesystem again, which can very well be the next time the system boots. * This happens because if udev blkid detects more than one filesystem, it does not print the UUID env vars required to create the /dev/disk/by-id symlinks and other things. * The fix enhances the check for valid nilfs superblock by specifically checking a value read from disk to be valid/ within a value range, which addresses this one occurrence and prevents a lot more.
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
This problem can be reproduced with a synthetic test case.
Essentially,
1) create a zero-filled disk image with one partition.
2) format it as ext4.
3) insert the nilfs2 magic bytes at the right position.
4) insert the nilfs2 bytes field at the right position.
--
Step 1)
# dd if=/dev/zero of=test.img bs=512 count=$((16 * 2048)) # 16
MiB
# dev=$(losetup --find --show test.img)
# parted $dev --script 'mklabel msdos'
# parted $dev --script "mkpart primary 1s $((16 * 2048 - 1))s"
# parted $dev --script 'unit s' --script 'print'
Model: Loopback device (loopback)
Disk /dev/loop0: 32768s
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:
Number Start End SizeType File system Flags
1 1s 32767s 32767s primary
# hexdump -C $dev
... ...
*
01f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa
|..U.|
0200 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
||
*
0100
# printf '\x00\x00\x00\x00\x00\x00\x34\x34' | hexdump -C
00 00 00 00 00 00 34 34 |..44|
0008
# partprobe $dev
# part=${dev}p1
Step 2)
# mkfs.ext4 $part
Steps 3 and 4)
From gdb/source:
(gdb) ptype/o struct nilfs_super_block
/* offset| size */ type = struct nilfs_super_block {
...
/*6 | 2 */uint16_t s_magic;
/*8 | 2 */uint16_t s_bytes;
...
#define NILFS_SB_MAGIC 0x3434
#define NILFS_SB_OFFSET 0x400
#define NILFS_SBB_OFFSET(_sz) _sz) / 0x200) - 8) * 0x200)
Then (magic is 0x3434, bytes is 0x0401 == 1025 in litte endian
-- value targeted at the fix)
# printf '\x00\x00\x00\x00\x00\x00\x34\x34\x01\x04' | dd
of=$part bs=1 count=10 conv=notrunc seek=$(( ( (16 * 2048 - 1) - 8) *
512 ))
# hexdump -C $part
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
||
*
00ffee00 00 00 00 00 00 00 34 34 01 04 00 00 00 00 00 00
|..44|
00ffee10 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
||
*
00fffe00
Original Package)
# LIBBLKID_DEBUG=all udevadm test-builtin blkid /sys/block/$(basename
$dev)/$(basename $part)
...
9576: libblkid: LOWPROBE: [28] ext4:
9576: libblkid: LOWPROBE: reuse buffer: off=1024 len=1024
pr=0x55744f2daec0
9576: libblkid: LOWPROBE: magic sboff=56, kboff=1
9576: libblkid: LOWPROBE: call probefunc()
9576: libblkid: LOWPROBE: reuse buffer: off=1024 len=1024
pr=0x55744f2daec0
9576: libblkid:PROBE: ext2_sb.compat = 003C:0242:007B
9576: libblkid: LOWPROBE: assigning UUID [superblocks]
9576: libblkid: LOWPROBE: assigning VERSION [superblocks]
9576: libblkid: LOWPROBE: assigning TYPE [superblocks]
9576: libblkid: LOWPROBE: assigning USAGE [superblocks]
9576: libblkid: LOWPROBE: <-- leaving probing loop (type=ext4) [SUBLKS
idx=28]
...
9576: libblkid: LOWPROBE: [63] nilfs2:
9576: libblkid: LOWPROBE: call probefunc()
9576: libblkid: LOWPROBE: reuse buffer: off=1024 len=1024
pr=0x55744f2daec0
9576: libblkid: LOWPROBE: reuse buffer: off=16772608 len=4096
pr=0x55744f2daec0
9576: libblkid: LOWPROBE: incorrect checksum for type nilfs2, got
2C077E8F, expected 0
9576: libblkid: LOWPROBE: assigning SBBADCSUM [superblocks]
9576: libblkid: LOWPROBE: nilfs2: primary=0, backup=1, swap=1
9576: libblkid: LOWPROBE: assigning VERSION [superblocks]
9576: libblkid: LOWPROBE: assigning TYPE [superblocks]
9576: libblkid: LOWPROBE: assigning USAGE [superblocks]
9576: libblkid: LOWPROBE: <-- leaving probing loop (type=nilfs2)
[SUBLKS idx=63]
...
9576: libblkid: LOWPROBE: ERROR: superblocks chain: ambivalent result
detected (2 filesystems)!
...
# echo $?
1
Original Package with Debug Print)
9604: libblkid: LOWPROBE: [63] nilfs2:
9604: libblkid: LOWPROBE: call probefunc()
9604: libblkid: LOWPROBE: reuse buffer: off=1024 len=1024
pr=0x55c076c8eec0
9604: libblkid: LOWPROBE: reuse buffer: off=16772608 len=4096
pr=0x55c076c8eec0
9604: libblkid: LOWPROBE: nilfs2: nilfs_valid_sb:77 :: entry
9604: libblkid: LOWPROBE: nilfs2: nilfs_valid_sb:80 :: not sb or not
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
modified package: # dpkg -s libblkid1 | grep ^Version: Version: 2.27.1-6ubuntu3.8+test20190903b1 # LIBBLKID_DEBUG=all udevadm test-builtin blkid /sys/block/loop0/loop0p1 ... 7289: libblkid: LOWPROBE: [28] ext4: 7289: libblkid: LOWPROBE: reuse buffer: off=1024 len=1024 pr=0x5604292b7ec0 7289: libblkid: LOWPROBE: magic sboff=56, kboff=1 7289: libblkid: LOWPROBE: call probefunc() 7289: libblkid: LOWPROBE: reuse buffer: off=1024 len=1024 pr=0x5604292b7ec0 7289: libblkid:PROBE: ext2_sb.compat = 003C:0246:007B 7289: libblkid: LOWPROBE: assigning UUID [superblocks] 7289: libblkid: LOWPROBE: assigning VERSION [superblocks] 7289: libblkid: LOWPROBE: assigning TYPE [superblocks] 7289: libblkid: LOWPROBE: assigning USAGE [superblocks] ... 7289: libblkid: LOWPROBE: [63] nilfs2: 7289: libblkid: LOWPROBE: call probefunc() 7289: libblkid: LOWPROBE: reuse buffer: off=1024 len=1024 pr=0x5604292b7ec0 7289: libblkid: LOWPROBE: reuse buffer: off=1072689152 len=4096 pr=0x5604292b7ec0 7289: libblkid: LOWPROBE: [64] exfat: ... 7289: libblkid: LOWPROBE: returning UUID value ID_FS_UUID=bac40f54-41c7-4a5a-a3f2-87bf23546e9c ... # echo $? 0 -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
udev builtin blkid ignores the checksum error:
nilfs_valid_sb() @ nilfs.c:96
return blkid_probe_verify_csum(pr, crc, le32_to_cpu(sb->s_sum));
blkid_probe_verify_csum() @ probe.c:1576-1687
if (csum != expected) {
...
DBG(LOWPROBE, ul_debug(
"incorrect checksum for type %s,"
" got %"PRIX64", expected %"PRIX64"",
...
* Accept bad checksum if BLKID_SUBLKS_BADCSUM flags is set
...
blkid_probe_set_value(pr, "SBBADCSUM", (unsigned char
*) "1", 2);
goto accept;
}
return 0; /* bad checksum */
...
accept:
return 1;
from debug:
586: libblkid: LOWPROBE: incorrect checksum for type nilfs2, got
56C7A81B, expected 2D2D206B
586: libblkid: LOWPROBE: assigning SBBADCSUM [superblocks]
and udev blkid uses that flag:
builtin_blkid() @ udev-builtin-blkid.c:264-268
blkid_probe_set_superblocks_flags(pr,
...
BLKID_SUBLKS_BADCSUM);
--
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to util-linux in Ubuntu.
https://bugs.launchpad.net/bugs/1842437
Title:
Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem
with udev
Status in util-linux package in Ubuntu:
Fix Released
Status in util-linux source package in Xenial:
In Progress
Bug description:
The nilfs filesystem has a backup superblock at the end of the device.
If the magic number is coincidentally found at the right position
and the filesystem is on a partition/not-wholedisk device,
the only check left is for checksum verification,
which is explicitly ignored in 'udev built-in blkid'.
This causes blkid to detect one actually valid filesystem with a
superblock at the beginning of the device (e.g., ext4), and then
an invalid nilfs2 filesystem due to a coincidental magic number
at the end of the device.
And this causes blkid to break out of the safeprobe routine
(which expects a single filesystem to be detected), and not
print the UUIDs, thus not creating /dev/disk/by-uuid/ links
which prevent mounting the partition by-uuid at boot time,
causing emergency shell/boot failures.
This upstream fix resolved the problem by introducing a check
for the 'bytes' paramenters in the superblock, which is read
from disk, and turns out to have an out-of-range value.
- 'liblkid: Add length check in probe_nilfs2 before crc32'
https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2
$ git describe --contains ac681a310c32319423297544833932f4d689a7a2
v2.29-rc1~172
Xenial, which is v2.27.1-based, is the only release that needs it.
Bionic is v2.31.1, so all post-Xenial supported releases have it.
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions
--
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Post to : touch-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~touch-packages
More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
with debug we could confirm that other fields in the backup superblock are invalid, such as the device size, which was not checked for not being a whole-disk device, and the bytes length, which is greater than the superblock structure size (8243 vs 1024). so, the fix to check for the bytes field not being out-of-range resolves this case. primary superblock 586: libblkid: LOWPROBE: nilfs2: nilfs_valid_sb:77 :: entry 586: libblkid: LOWPROBE: nilfs2: nilfs_valid_sb:80 :: not sb or not magic backup superblock 586: libblkid: LOWPROBE: nilfs2: nilfs_valid_sb:77 :: entry 586: libblkid: LOWPROBE: nilfs2: nilfs_valid_sb:84 :: is_bak 1 586: libblkid: LOWPROBE: nilfs2: nilfs_valid_sb:85 :: is_wholedisk 0 586: libblkid: LOWPROBE: nilfs2: nilfs_valid_sb:86 :: sb->s_dev_size 3_472_328_296_366_616_623 586: libblkid: LOWPROBE: nilfs2: nilfs_valid_sb:87 :: pr->size 1_072_693_248 586: libblkid: LOWPROBE: nilfs2: nilfs_valid_sb:96 :: bytes 8243 586: libblkid: LOWPROBE: incorrect checksum for type nilfs2, got 56C7A81B, expected 2D2D206B 586: libblkid: LOWPROBE: assigning SBBADCSUM [superblocks] 586: libblkid: LOWPROBE: nilfs2: primary=0, backup=1 586: libblkid: LOWPROBE: nilfs2: primary=0, backup=1, swap=1 -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
original package: # dpkg -s libblkid1 | grep ^Version: Version: 2.27.1-6ubuntu3.8 # LIBBLKID_DEBUG=all udevadm test-builtin blkid /sys/block/loop0/loop0p1 ... 4924: libblkid: LOWPROBE: [28] ext4: 4924: libblkid: LOWPROBE: reuse buffer: off=1024 len=1024 pr=0x55fe3cbdcec0 4924: libblkid: LOWPROBE: magic sboff=56, kboff=1 4924: libblkid: LOWPROBE: call probefunc() 4924: libblkid: LOWPROBE: reuse buffer: off=1024 len=1024 pr=0x55fe3cbdcec0 4924: libblkid:PROBE: ext2_sb.compat = 003C:0246:007B 4924: libblkid: LOWPROBE: assigning UUID [superblocks] 4924: libblkid: LOWPROBE: assigning VERSION [superblocks] 4924: libblkid: LOWPROBE: assigning TYPE [superblocks] 4924: libblkid: LOWPROBE: assigning USAGE [superblocks] ... 4924: libblkid: LOWPROBE: [63] nilfs2: 4924: libblkid: LOWPROBE: call probefunc() 4924: libblkid: LOWPROBE: reuse buffer: off=1024 len=1024 pr=0x55fe3cbdcec0 4924: libblkid: LOWPROBE: reuse buffer: off=1072689152 len=4096 pr=0x55fe3cbdcec0 4924: libblkid: LOWPROBE: incorrect checksum for type nilfs2, got 46498012, expected 2D2D206B 4924: libblkid: LOWPROBE: assigning SBBADCSUM [superblocks] 4924: libblkid: LOWPROBE: nilfs2: primary=0, backup=1, swap=1 4924: libblkid: LOWPROBE: assigning LABEL [superblocks] 4924: libblkid: LOWPROBE: assigning UUID [superblocks] 4924: libblkid: LOWPROBE: assigning VERSION [superblocks] 4924: libblkid: LOWPROBE: assigning TYPE [superblocks] 4924: libblkid: LOWPROBE: assigning USAGE [superblocks] ... 4924: libblkid: LOWPROBE: ERROR: superblocks chain: ambivalent result detected (2 filesystems)! ... # echo $? 1 -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1842437] Re: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev
Problem: - the ext4 filesystem is detected correctly at the beginning of the partition. - the nilfs2 filesystem is detected incorrectly at the end of the partition. - the nilfs2 checksum is invalid, but that is ignored by udev builtin blkid. - the detection of more than one filesystems causes an error and stop blkid. # LIBBLKID_DEBUG=all udevadm test-builtin blkid /sys/block/loop0/loop0p1 ... 30555: libblkid: LOWPROBE: [28] ext4: 30555: libblkid: LOWPROBE: reuse buffer: off=1024 len=1024 pr=0x558f3ea3dec0 30555: libblkid: LOWPROBE: magic sboff=56, kboff=1 30555: libblkid: LOWPROBE: call probefunc() 30555: libblkid: LOWPROBE: reuse buffer: off=1024 len=1024 pr=0x558f3ea3dec0 30555: libblkid:PROBE: ext2_sb.compat = 003C:0246:007B 30555: libblkid: LOWPROBE: assigning UUID [superblocks] 30555: libblkid: LOWPROBE: assigning VERSION [superblocks] 30555: libblkid: LOWPROBE: assigning TYPE [superblocks] 30555: libblkid: LOWPROBE: assigning USAGE [superblocks] ... 30555: libblkid: LOWPROBE: [63] nilfs2: 30555: libblkid: LOWPROBE: call probefunc() 30555: libblkid: LOWPROBE: reuse buffer: off=1024 len=1024 pr=0x558f3ea3dec0 30555: libblkid: LOWPROBE: reuse buffer: off=1072689152 len=4096 pr=0x558f3ea3dec0 30555: libblkid: LOWPROBE: incorrect checksum for type nilfs2, got 3F8DC6BA, expected 2D2D206B 30555: libblkid: LOWPROBE: assigning SBBADCSUM [superblocks] 30555: libblkid: LOWPROBE: nilfs2: primary=0, backup=1, swap=1 30555: libblkid: LOWPROBE: assigning LABEL [superblocks] 30555: libblkid: LOWPROBE: assigning UUID [superblocks] 30555: libblkid: LOWPROBE: assigning VERSION [superblocks] 30555: libblkid: LOWPROBE: assigning TYPE [superblocks] 30555: libblkid: LOWPROBE: assigning USAGE [superblocks] ... 30555: libblkid: LOWPROBE: ERROR: superblocks chain: ambivalent result detected (2 filesystems)! ... # echo $? 1 -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1842437 Title: Xenial: libblkid: fix false-positive/misdetection of nilfs2 filesystem with udev Status in util-linux package in Ubuntu: Fix Released Status in util-linux source package in Xenial: In Progress Bug description: The nilfs filesystem has a backup superblock at the end of the device. If the magic number is coincidentally found at the right position and the filesystem is on a partition/not-wholedisk device, the only check left is for checksum verification, which is explicitly ignored in 'udev built-in blkid'. This causes blkid to detect one actually valid filesystem with a superblock at the beginning of the device (e.g., ext4), and then an invalid nilfs2 filesystem due to a coincidental magic number at the end of the device. And this causes blkid to break out of the safeprobe routine (which expects a single filesystem to be detected), and not print the UUIDs, thus not creating /dev/disk/by-uuid/ links which prevent mounting the partition by-uuid at boot time, causing emergency shell/boot failures. This upstream fix resolved the problem by introducing a check for the 'bytes' paramenters in the superblock, which is read from disk, and turns out to have an out-of-range value. - 'liblkid: Add length check in probe_nilfs2 before crc32' https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=ac681a310c32319423297544833932f4d689a7a2 $ git describe --contains ac681a310c32319423297544833932f4d689a7a2 v2.29-rc1~172 Xenial, which is v2.27.1-based, is the only release that needs it. Bionic is v2.31.1, so all post-Xenial supported releases have it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1842437/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
