CVE-2022-48858

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>