Linux Kernel up to 7.1.7/7.2-rc5 AMD Display drm/amd/display calculate_mcache_setting divide by zero

Summaryinfo

A vulnerability classified as critical was found in Linux Kernel up to 7.1.7/7.2-rc5. The impacted element is the function calculate_mcache_setting of the file drm/amd/display of the component AMD Display. Such manipulation leads to divide by zero. This vulnerability is uniquely identified as CVE-2026-74449. Local access is required to approach this attack. No exploit exists.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 7.1.7/7.2-rc5. Affected by this issue is the function calculate_mcache_setting of the file drm/amd/display of the component AMD Display. The manipulation with an unknown input leads to a divide by zero vulnerability. Using CWE to declare the problem leads to CWE-369. The product divides a value by zero. Impacted is availability. CVE summarizes:

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)

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2026-74449 since 08/15/2026. The exploitation is known to be easy. Local access is required to approach this attack. Technical details are known, but there is no available exploit.

Upgrading to version 7.1.8 or 7.2-rc6 eliminates this vulnerability. Applying the patch 1f93537881fd22712732a60ad12572a3fd40c0ec/f327e389c07cfc3a2f6ff54f6214e1a52d457edc is able to eliminate this problem.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 7.1.0
• 7.1.1
• 7.1.2
• 7.1.3
• 7.1.4
• 7.1.5
• 7.1.6
• 7.1.7
• 7.2-rc1
• 7.2-rc2
• 7.2-rc3
• 7.2-rc4
• 7.2-rc5

License

• open-source

Website

• Vendor: https://www.kernel.org/

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