@juliank, is this an aws system? If not there's a good chance that you are using an initramfs to mount the filesystems. That's definited in either /etc/init.d/udev or directly out of the init that lives in the initramfs.
-- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1991975 Title: dev file system is mounted without nosuid or noexec Status in linux package in Ubuntu: Confirmed Status in systemd package in Ubuntu: Confirmed Status in linux source package in Focal: Confirmed Status in systemd source package in Focal: Confirmed Status in linux source package in Jammy: Confirmed Status in systemd source package in Jammy: Confirmed Bug description: [ SRU TEMPLATE ] [ Impact ] * nosuid, and noexec bits are not set on /dev * This has the potential for nefarious actors to use this as an avenue for attack. see https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1450960 for more discussion around this. * It is not best security practice. [ Test Plan ] 1.Boot a Canonical Supplied EC2 instance 2.Check the mount options for /dev. 3.You will notice the lack of nosuid and noexec on /dev. [ Where problems could occur ] * As of 2022/10/06, I need to test this, but don't know how to build -aws flavored ubuntu kernels. Instructions welcome. I'm holding off on adding SRU tags until I can actually get this tested. * If this is applied to non initramfs-less kernels it could potentially cause a regression for very old hardware that does nefarious things with memory. For a larger discussion about that see: https://lore.kernel.org/lkml/YcMfDOyrg647RCmd@debian-BULLSEYE-live-builder-AMD64/T/ * Low risk if a driver depends on /dev allowing suid or exec this might prevent boot. That being said, all kernels that have been booting with an initramfs have been getting nosuid, and noexec set so hopefully we can consider that risk fairly well tested. [ Other Info ] * Patch is accepted into 5.17, and will drop out quickly * Any server booting with an initramfs already has nosuid, and noexec set, so hopefully <<<<<<< ORIGINAL TEXT >>>>>>>>>>>> This is similar to https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1450960 but new. I discovered that my ec2 instances based off of Canonical supplied AMI ami-0a23d90349664c6ee *(us-east-2), have dev mounted mounted without the nosuid option. https://us-east-2.console.aws.amazon.com/ec2/home?region=us- east-2#Images:visibility=public-images;imageId=ami-0a23d90349664c6ee My usb installed 20.04.4 home machine does not have this problem, but it has been installed for quite some time. My 22.04 laptop machine also does not have this issue. Reproduce. Start an ec2 instance based off of ami-0a23d90349664c6ee. $ mount | grep devtmpfs nosuid is not found in the options list. I've checked the initrd, and /etc/init.d/udev script and all places I know of where dev gets mounted set nosuid, so it's non-obvious what boot code-path is being taken that results in nosuid missing. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: udev 245.4-4ubuntu3.18 ProcVersionSignature: Ubuntu 5.15.0-1020.24~20.04.1-aws 5.15.53 Uname: Linux 5.15.0-1020-aws x86_64 ApportVersion: 2.20.11-0ubuntu27.24 Architecture: amd64 CasperMD5CheckResult: skip CustomUdevRuleFiles: 60-cdrom_id.rules 70-snap.snapd.rules Date: Thu Oct 6 17:39:42 2022 Ec2AMI: ami-0a23d90349664c6ee Ec2AMIManifest: (unknown) Ec2AvailabilityZone: us-east-2c Ec2InstanceType: t2.medium Ec2Kernel: unavailable Ec2Ramdisk: unavailable Lsusb: Error: command ['lsusb'] failed with exit code 1: Lsusb-t: Lsusb-v: Error: command ['lsusb', '-v'] failed with exit code 1: MachineType: Xen HVM domU ProcEnviron: TERM=xterm-256color PATH=(custom, no user) LANG=C.UTF-8 SHELL=/bin/bash ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.15.0-1020-aws root=PARTUUID=5bb90437-9efc-421d-aa94-c512c3b666a3 ro console=tty1 console=ttyS0 nvme_core.io_timeout=4294967295 panic=-1 SourcePackage: systemd UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 08/24/2006 dmi.bios.release: 4.2 dmi.bios.vendor: Xen dmi.bios.version: 4.2.amazon dmi.chassis.type: 1 dmi.chassis.vendor: Xen dmi.modalias: dmi:bvnXen:bvr4.2.amazon:bd08/24/2006:br4.2:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:sku: dmi.product.name: HVM domU dmi.product.version: 4.2.amazon dmi.sys.vendor: Xen To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1991975/+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
