Bug 2516997 (CVE-2026-74449) - CVE-2026-74449 kernel: drm/amd/display: Fix divide-by-zero in calculate_mcache_setting on zero viewport
Summary: CVE-2026-74449 kernel: drm/amd/display: Fix divide-by-zero in calculate_mcach...
Keywords:
Status: NEW
Alias: CVE-2026-74449
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-15 12:43 UTC by OSIDB Bzimport
Modified: 2026-09-03 14:32 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2026-08-15 12:43:51 UTC
In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: Fix divide-by-zero in calculate_mcache_setting on zero viewport

If a plane reaches calculate_mcache_setting with a zero-area viewport,
calculate_mcache_setting exits early with num_mcaches == 0 and
mvmpg_width/height == 0. This will cause a divide-by-zero panic and can
also cause an underflow on num_mcaches.

Fix this by changing calculate_mcache_setting to bool and adding guards
after each calculate_mcache_row_bytes call. If num_mcaches or
mvmpg_width/height is zero, return a false. Callers will propagate the
failure as a rejected mode, which prevents the panic.

(cherry picked from commit 29c0f7c655f47bcbd575ff75e58480df6ec3c9da)


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