From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-89819: drm/amd/display: validate plane degamma LUT size for private color prop
Date: Wed, 16 Sep 2026 11:29:09 +0100 [thread overview]
Message-ID: <2026091600-CVE-2026-89819-e5fd@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: validate plane degamma LUT size for private color prop
Unlike the CRTC degamma path, which is guarded by
amdgpu_dm_verify_lut_sizes(), the per-plane degamma LUT size was never
validated before use. __set_dm_plane_degamma() passed the user-supplied
size straight into __is_lut_linear() and, for a non-linear LUT, into
__set_input_tf() -> __drm_lut_to_dc_gamma(), the latter always iterating
MAX_COLOR_LUT_ENTRIES entries regardless of the actual LUT size.
A malformed AMD_PLANE_DEGAMMA_LUT blob (e.g. a single entry) could thus
trigger a divide-by-zero in __is_lut_linear() or an out-of-bounds read in
__drm_lut_to_dc_gamma(). Reject any plane degamma LUT whose size does not
match MAX_COLOR_LUT_ENTRIES, mirroring the invariant the code already
asserts a few lines below (and which the CRTC path enforces).
The AMD_PLANE_DEGAMMA_LUT property is only exposed on builds with
AMD_PRIVATE_COLOR defined.
The Linux kernel CVE team has assigned CVE-2026-89819 to this issue.
Affected and fixed versions
===========================
Issue introduced in 6.8 with commit 980f8710075acaeb226a94cde6dda8ffad30123c and fixed in 6.12.110 with commit f6f04d8ae5725bcc893bdc62e3467efd97255c5b
Issue introduced in 6.8 with commit 980f8710075acaeb226a94cde6dda8ffad30123c and fixed in 6.18.51 with commit 0b2615b8b54f58bbdf986dffb38cbc35214a5cc5
Issue introduced in 6.8 with commit 980f8710075acaeb226a94cde6dda8ffad30123c and fixed in 7.2.5 with commit b10cc09b329245c6d95f8fa3e7f068575e3e0e9f
Issue introduced in 6.8 with commit 980f8710075acaeb226a94cde6dda8ffad30123c and fixed in 7.3-rc1 with commit e4c3ab59021e7c146a84b6671f0d530972bd58b4
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-2026-89819
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/amd/display/amdgpu_dm/amdgpu_dm_color.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/f6f04d8ae5725bcc893bdc62e3467efd97255c5b
https://git.kernel.org/stable/c/0b2615b8b54f58bbdf986dffb38cbc35214a5cc5
https://git.kernel.org/stable/c/b10cc09b329245c6d95f8fa3e7f068575e3e0e9f
https://git.kernel.org/stable/c/e4c3ab59021e7c146a84b6671f0d530972bd58b4
reply other threads:[~2026-09-16 10:33 UTC|newest]
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