Withdrawn by the publisher.

In the Linux kernel, the following vulnerability has been resolved:

f2fs: protect critical_task_priority updates with s_umount

The sysfs store path already takes s_umount for GC thread control entries, and ckpt_thread_ioprio is covered as well.

critical_task_priority also updates checkpoint or GC kthread scheduling state, but it is not covered by that serialization. It can race with remount or teardown paths that are stopping those threads.

Protect critical_task_priority sysfs writes with s_umount too.

In the Linux kernel, the following vulnerability has been resolved:

f2fs: protect critical_task_priority updates with s_umount

The sysfs store path already takes s_umount for GC thread control entries, and ckpt_thread_ioprio is covered as well.

critical_task_priority also updates checkpoint or GC kthread scheduling state, but it is not covered by that serialization. It can race with remount or teardown paths that are stopping those threads.

Protect critical_task_priority sysfs writes with s_umount too.

kernel-devel-7.2.7-1.1 on GA media

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 118 more

In the Linux kernel, the following vulnerability has been resolved: f2fs: protect critical_task_priority updates with s_umount The sysfs store path already takes s_umount for GC thread control entries, and ckpt_thread_ioprio is covered as well. critical_task_priority also updates checkpoint or GC kthread scheduling state, but it is not covered by that serialization. It can race with remount or teardown paths that are stopping those threads. Protect critical_task_priority sysfs writes with s_umount too.