Subject: CVE-2024-38622: drm/msm/dpu: Add callback function pointer check before its call

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

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

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

drm/msm/dpu: Add callback function pointer check before its call

In dpu_core_irq_callback_handler() callback function pointer is compared to NULL,
but then callback function is unconditionally called by this pointer.
Fix this bug by adding conditional return.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Patchwork: https://patchwork.freedesktop.org/patch/588237/

The Linux kernel CVE team has assigned CVE-2024-38622 to this issue.

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

	Issue introduced in 5.19 with commit c929ac60b3ed and fixed in 6.6.33 with commit 873f67699114
	Issue introduced in 5.19 with commit c929ac60b3ed and fixed in 6.9.4 with commit 9078630ed7f8
	Issue introduced in 5.19 with commit c929ac60b3ed and fixed in 6.10 with commit 530f272053a5

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-2024-38622
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/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.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/873f67699114452c2a996c4e10faac8ff860c241
	https://git.kernel.org/stable/c/9078630ed7f8f25d65d11823e7f2b11a8e2f4f0f
	https://git.kernel.org/stable/c/530f272053a5e72243a9cb07bb1296af6c346002