CVE-2026-74417: drm/radeon: fix integer overflow in radeon_align_pitch()

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

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

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

drm/radeon: fix integer overflow in radeon_align_pitch()

radeon_align_pitch() has the same kind of overflow issue as the old
amdgpu helper: both the alignment round-up add and the final
'aligned * cpp' calculation can overflow signed int.

If that wraps, radeon_mode_dumb_create() can end up returning an
invalid pitch or creating a zero-sized dumb buffer.

Fix this by using check_add_overflow() for the alignment round-up and
check_mul_overflow() for the final pitch calculation, returning 0 on
overflow. Also reject zero pitch and size in
radeon_mode_dumb_create().

Found via AST-based call-graph analysis using sqry.

The Linux kernel CVE team has assigned CVE-2026-74417 to this issue.


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

	Issue introduced in 2.6.39 with commit ff72145badb834e8051719ea66e024784d000cb4 and fixed in 6.6.145 with commit b7b44937c548c2c987fcdd129f8896741004bed6
	Issue introduced in 2.6.39 with commit ff72145badb834e8051719ea66e024784d000cb4 and fixed in 6.12.97 with commit 415bb9893e249e46aa5159f7363a11512cf06fa9
	Issue introduced in 2.6.39 with commit ff72145badb834e8051719ea66e024784d000cb4 and fixed in 6.18.40 with commit d9dfa176899d488e48bb7342d2c43ddd36e66318
	Issue introduced in 2.6.39 with commit ff72145badb834e8051719ea66e024784d000cb4 and fixed in 7.1.5 with commit dfc7b5b5599472277e71e5bd2712740651c7c5be
	Issue introduced in 2.6.39 with commit ff72145badb834e8051719ea66e024784d000cb4 and fixed in 7.2-rc1 with commit ce3b24eb3ee8f82de851535f516bf21f83e82259

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-2026-74417
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/radeon/radeon_gem.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/b7b44937c548c2c987fcdd129f8896741004bed6
	https://git.kernel.org/stable/c/415bb9893e249e46aa5159f7363a11512cf06fa9
	https://git.kernel.org/stable/c/d9dfa176899d488e48bb7342d2c43ddd36e66318
	https://git.kernel.org/stable/c/dfc7b5b5599472277e71e5bd2712740651c7c5be
	https://git.kernel.org/stable/c/ce3b24eb3ee8f82de851535f516bf21f83e82259