Performing verification for Jammy. I started a fresh Jammy VM, and installed 5.15.0-67-generic from -updates.
I appended apparmor=0 to GRUB_CMDLINE_LINUX_DEFAULT, updated grub, and rebooted. >From there, I installed auditd, and stress-ng. I edited /etc/audit/rules.d/audit.rules to include: -a exit,always -F arch=b64 -S execve -a exit,always -F arch=b32 -S execve I then rebooted, and started stress-ng. I checked the kmalloc-2k slab with: $ watch "sudo cat /proc/meminfo | grep SUnreclaim" $ watch "sudo cat /proc/slabinfo | grep kmalloc-2k" $ sudo slabtop Now, since this bug has been worked around by: 39cce16cfeed UBUNTU: SAUCE: LSM: Change Landlock from LSMBLOB_NEEDED to LSMBLOB_NOT_NEEDED in 5.15.0-53-generic, the kmalloc-k slab did not uncontrollably increase, but that is okay, it is just the leak isn't reachable with landlock not using the task_getsecid_obj hook. This means this verification is more of a smoke test than checking root cause. I then enabled -proposed, and installed 5.15.0-68-generic, and rebooted. I again ran stress-ng and checked the kmalloc-2k slab, and all was well, there was no memory leak. The core issue was fixed, but again, masked by the previous fix in 5.15.0-53-generic. There was no smoke, and things ran as expected. Marking verified for Jammy. ** Tags removed: verification-needed-jammy ** Tags added: verification-done-jammy -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1987430 Title: Ubuntu 22.04 kernel 5.15.0-46-generic leaks kernel memory in kmalloc-2k slabs Status in linux package in Ubuntu: In Progress Status in linux source package in Jammy: Fix Committed Status in linux source package in Kinetic: Fix Released Bug description: Since updating to kernel 5.15.0-46-generic (package version 5.15.0-46.49), all of our Ubuntu 22.04 LTS servers are leaking kernel memory; our first server with 8 GB of RAM just fatally OOMed, causing us to detect this. Inspection of OOM reports, /proc/meminfo, and /proc/slabinfo says that it's mostly going to unreclaimable kmalloc-2k slabs: Aug 23 12:51:11 cluster kernel: [361299.864757] Unreclaimable slab info: Aug 23 12:51:11 cluster kernel: [361299.864757] Name Used Total [...] Aug 23 12:51:11 cluster kernel: [361299.864924] kmalloc-2k 6676584KB 6676596KB Most of our machines appear to be leaking slab memory at a rate of around 20 to 40 Mbytes/hour, with some machines leaking much faster; the champions are leaking kernel memory at 145 Mbytes/hour and 237 Mbytes/hour. We aren't running any proprietary kernel modules and our only unusual kernel configuration is that we've disabled AppArmor with 'apparmor=0' on the kernel command line. /proc/version_signature: Ubuntu 5.15.0-46.49-generic 5.15.39 Full kernel command line from the Dell R240 system that fatally OOMd: BOOT_IMAGE=/boot/vmlinuz-5.15.0-46-generic root=UUID=3165564f-a2dd-4b39-935b-114f3e23ff54 ro console=ttyS0,115200 console=tty0 apparmor=0 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1987430/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
