Bug 2298199 (CVE-2022-48858)

Summary:	CVE-2022-48858 kernel: net/mlx5: Fix a race on command flush flow
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	dfreiber, drow, jburrell, vkumar
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 5.4.185, kernel 5.10.106, kernel 5.15.29, kernel 5.16.15, kernel 5.17	Doc Type:	If docs needed, set a value
Doc Text:	A vulnerability was found in the Linux kernel's mlx5 driver in the command flush handling, which allows a race condition, when one command releases its reference count and frees its associated entry while another process attempts to flush commands, leading to a use-after-free condition.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2024-07-16 13:26:07 UTC

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>