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

io_uring: always do atomic put from iowq

io_uring always switches requests to atomic refcounting for iowq
execution before there is any parallilism by setting REQ_F_REFCOUNT,
and the flag is not cleared until the request completes. That should be
fine as long as the compiler doesn't make up a non existing value for
the flags, however KCSAN still complains when the request owner changes
oter flag bits:

BUG: KCSAN: data-race in io_req_task_cancel / io_wq_free_work
...
read to 0xffff888117207448 of 8 bytes by task 3871 on cpu 0:
 req_ref_put_and_test io_uring/refs.h:22 [inline]

Skip REQ_F_REFCOUNT checks for iowq, we know it's set.

Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.

kernel.org: https://git.kernel.org/stable/c/3568fd9e440ea393c7d8bee253419ea11fd8e9d9

kernel.org: https://git.kernel.org/stable/c/390513642ee6763c7ada07f0a1470474986e6c1c

kernel.org: https://git.kernel.org/stable/c/6d2753b46452a557a12f7ef1ef4ee6641b4e89d8

kernel.org: https://git.kernel.org/stable/c/c5d4d103005d8926cdad344f9fc947e651c9f2f7