CVE-2026-98016: net/mlx5e: Fix use-after-free race in sample_restore_put()

CVE-2026-98016: net/mlx5e: Fix use-after-free race in sample_restore_put()

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

Description
===========

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

net/mlx5e: Fix use-after-free race in sample_restore_put()

Concurrent teardown of TC sample rules sharing the same restore
context may re-read restore->count after dropping restore_lock.
At that point another thread may already have completed cleanup and
freed the restore object.

Use the result of the refcount decrement while holding restore_lock to
determine whether cleanup is needed.

The Linux kernel CVE team has assigned CVE-2026-98016 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 5.13 with commit 36a3196256bf3310e5e7142b0e61787f7a201abd and fixed in 6.12.111 with commit 3efd1a1938cbb33c53b0d75e55b6c0fe2ebad79a
	Issue introduced in 5.13 with commit 36a3196256bf3310e5e7142b0e61787f7a201abd and fixed in 6.18.53 with commit 72324da8eeca269db9196c2a555abf72eb0385c5
	Issue introduced in 5.13 with commit 36a3196256bf3310e5e7142b0e61787f7a201abd and fixed in 7.2.7 with commit 1daecd76ab9e5f055fe3970462410ad1d40bd177
	Issue introduced in 5.13 with commit 36a3196256bf3310e5e7142b0e61787f7a201abd and fixed in 7.3-rc3 with commit af3aef0245abbab5e9f6302e7a7d6407187afb71

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-98016
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/net/ethernet/mellanox/mlx5/core/en/tc/sample.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/3efd1a1938cbb33c53b0d75e55b6c0fe2ebad79a
	https://git.kernel.org/stable/c/72324da8eeca269db9196c2a555abf72eb0385c5
	https://git.kernel.org/stable/c/1daecd76ab9e5f055fe3970462410ad1d40bd177
	https://git.kernel.org/stable/c/af3aef0245abbab5e9f6302e7a7d6407187afb71