In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: Fix a race on command flush flow
Fix a refcount use after free warning due to a race on command entry.
Such race occurs when one of the commands releases its last refcount and
frees its index and entry while another process running command flush
flow takes refcount to this command entry. The process which handles
commands flush may see this command as needed to be flushed if the other
process released its refcount but didn’t release the index yet. Fix it
by adding the needed spin lock.
It fixes the following warning trace:
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 11 PID: 540311 at lib/refcount.c:25 refcount_warn_saturate+0x80/0xe0
…
RIP: 0010:refcount_warn_saturate+0x80/0xe0
…
Call Trace:
<TASK>
mlx5_cmd_trigger_completions+0x293/0x340 [mlx5_core]
mlx5_cmd_flush+0x3a/0xf0 [mlx5_core]
enter_error_state+0x44/0x80 [mlx5_core]
mlx5_fw_fatal_reporter_err_work+0x37/0xe0 [mlx5_core]
process_one_work+0x1be/0x390
worker_thread+0x4d/0x3d0
? rescuer_thread+0x350/0x350
kthread+0x141/0x160
? set_kthread_struct+0x40/0x40
ret_from_fork+0x1f/0x30
</TASK>
git.kernel.org/stable/c/0401bfb27a91d7bdd74b1635c1aae57cbb128da6
git.kernel.org/stable/c/063bd355595428750803d8736a9bb7c8db67d42d
git.kernel.org/stable/c/1a4017926eeea56c7540cc41b42106746ee8a0ee
git.kernel.org/stable/c/7c519f769f555ff7d9d4ccba3497bbb589df360a
git.kernel.org/stable/c/f3331bc17449f15832c31823f27573f4c0e13e5f