Public bug reported: It appears that an cgroup-OOM-killed process can cause a kernel panic/reboot.
Affected system: - Ubuntu/Noble - kernel 6.8.0-138-generic - zfs 2.2.2-0ubuntu9.5 This has been documented here: https://github.com/openzfs/zfs/issues/15918 - "kernel BUG at mm/usercopy.c:102" Fix is here: https://github.com/openzfs/zfs/pull/18408 - landed in 2.4.2 Request for backport to 2.2.x is here: https://github.com/openzfs/zfs/issues/19149 In my case the logs look like: ``` SOMETHING invoked oom-killer: gfp_mask=0xcc0(GFP_KERNEL), order=0, oom_score_adj=999 ... Memory cgroup stats for /kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod3015e4bc_2688_43c1_bcbe_a918dd63b8b9.slice: ... usercopy: Kernel memory exposure attempt detected from vmalloc 'no area' (offset 0, size 21058)! ``` Only that last message points to the actual bug. The OOM itself is just noise that precedes the bug. In our case, no additional logs were found, probably because the system rebooted before ZFS had a chance to commit the logs. This has happened twice on the same system in September now. Filing the bug here so others can see it too. If it happens often enough, maybe it's time for a backport. Cheers, Walter Doekes OSSO B.V. ** Affects: zfs-linux (Ubuntu) Importance: Undecided Status: New ** Description changed: It appears that an cgroup-OOM-killed process can cause a kernel panic/reboot. Affected system: - Ubuntu/Noble - kernel 6.8.0-138-generic - zfs 2.2.2-0ubuntu9.5 This has been documented here: https://github.com/openzfs/zfs/issues/15918 - "kernel BUG at mm/usercopy.c:102" Fix is here: https://github.com/openzfs/zfs/pull/18408 - landed in 2.4.2 Request for backport to 2.2.x is here: https://github.com/openzfs/zfs/issues/19149 - In my case the looks like: + In my case the logs look like: ``` SOMETHING invoked oom-killer: gfp_mask=0xcc0(GFP_KERNEL), order=0, oom_score_adj=999 ... Memory cgroup stats for /kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod3015e4bc_2688_43c1_bcbe_a918dd63b8b9.slice: ... usercopy: Kernel memory exposure attempt detected from vmalloc 'no area' (offset 0, size 21058)! ``` Only that last message points to the actual bug. The OOM itself is just noise that precedes the bug. In our case, no additional logs were found, probably because the system rebooted before ZFS had a chance to commit the logs. This has happened twice on the same system in September now. Filing the bug here so others can see it too. If it happens often enough, maybe it's time for a backport. Cheers, Walter Doekes OSSO B.V. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2168414 Title: usercopy: Kernel memory exposure attempt detected from vmalloc To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/zfs-linux/+bug/2168414/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
