An issue was discovered in the Linux kernel 5.10.x before 5.10.155. A use-after-free in io_sqpoll_wait_sq in fs/io_uring.c allows an attacker to crash the kernel, resulting in denial of service. finish_wait can be skipped. An attack can occur in some situations by forking a process and then quickly terminating it. NOTE: later kernel versions, such as the 5.15 longterm series, substantially changed the implementation of io_sqpoll_wait_sq.
Created kernel tracking bugs for this issue:
Affects: fedora-36 [bug 2156539]
Affects: fedora-37 [bug 2156540]
(In reply to Alex from comment #2)
> Created kernel tracking bugs for this issue:
> Affects: fedora-36 [bug 2156539]
> Affects: fedora-37 [bug 2156540]
We typically create a single Fedora tracking bug which covers all releases. As I keep all Fedora releases on the same kernel version, maintained out of the same source tree, it either impacts all or none, and updates are filed at the same time for all releases.
This was fixed for Fedora with the 5.12 kernel rebases.