Subject: CVE-2024-43833: media: v4l: async: Fix NULL pointer dereference in adding ancillary links

From: Greg Kroah-Hartman <[email-masked]>

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

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

media: v4l: async: Fix NULL pointer dereference in adding ancillary links

In v4l2_async_create_ancillary_links(), ancillary links are created for
lens and flash sub-devices. These are sub-device to sub-device links and
if the async notifier is related to a V4L2 device, the source sub-device
of the ancillary link is NULL, leading to a NULL pointer dereference.
Check the notifier's sd field is non-NULL in
v4l2_async_create_ancillary_links().

[Sakari Ailus: Reword the subject and commit messages slightly.]

The Linux kernel CVE team has assigned CVE-2024-43833 to this issue.

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

	Issue introduced in 5.19 with commit aa4faf6eb271 and fixed in 6.1.103 with commit fe0f92fd5320
	Issue introduced in 5.19 with commit aa4faf6eb271 and fixed in 6.6.44 with commit 249212ceb418
	Issue introduced in 5.19 with commit aa4faf6eb271 and fixed in 6.10.3 with commit b87e28050d9b
	Issue introduced in 5.19 with commit aa4faf6eb271 and fixed in 6.11 with commit 9b4667ea6785

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-2024-43833
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/media/v4l2-core/v4l2-async.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/fe0f92fd5320b393e44ca210805e653ea90cc982
	https://git.kernel.org/stable/c/249212ceb4187783af3801c57b92a5a25d410621
	https://git.kernel.org/stable/c/b87e28050d9b0959de24574d587825cfab2f13fb
	https://git.kernel.org/stable/c/9b4667ea67854f0b116fe22ad11ef5628c5b5b5f