CVE-2026-89821
Published Sep 16, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: avoid divide-by-zero in __is_lut_linear() __is_lut_linear() computes the expected value of each entry with expected = i * MAX_DRM_LUT_VALUE / (size - 1); If it is ever called with a single-entry LUT, size - 1 is zero and the kernel takes a divide error (#DE). A LUT with fewer than two entries cannot describe a linear mapping anyway, so return false early instead of dividing by zero.
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References
Other References
https://git.kernel.org/stable/c/15ee43aad0df43dfd1dbb32e7d5b951745c4b87f
https://git.kernel.org/stable/c/2320626425f3af3a25b8afb6876f205b1c6d4e64
https://git.kernel.org/stable/c/4d5ee095a58461b2446d7a6eb0c14c2fe3eaab44
https://git.kernel.org/stable/c/4f40873f8a4107df2b9c8e68c947c4fd0cd519d2
https://git.kernel.org/stable/c/5f18cd1ba873e751bf5547407ad44ea34adfbe2f
https://git.kernel.org/stable/c/c127ace7af2b40107947a6504391f94d6fd21734
https://git.kernel.org/stable/c/d1e06d5dc8f12451ce71dc068342660a34476084
https://git.kernel.org/stable/c/ee28fafb50f58b847509b5240b431ddec673bdfe
Frequently Asked Questions
What is CVE-2026-89821? +
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: avoid divide-by-zero in __is_lut_linear()
__is_lut_linear() computes the expected value of each entry with
expected = i * MAX_DRM_LUT_VALUE / (size - 1);
If it is ever called with a single-entry LUT, size - 1 is zero and the
kernel takes a divide error (#DE). A LUT with fewer than two entries
cannot describe a linear mapping anyway, so return false early instead
of dividing by zero.
How do I check if I'm vulnerable to CVE-2026-89821? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.