CVE-2026-74449

Received Received - Intake

Divide-by-Zero in AMD Display Driver

Publication date: 2026-08-15

Last updated on: 2026-08-18

Assigner: kernel.org

Description

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)

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-08-15

Last Modified

2026-08-18

Generated

2026-09-04

AI Q&A

2026-08-15

EPSS Evaluated

2026-09-03

NVD

CVE-2026-74449

EUVD

EUVD-2026-59756

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	to 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (inc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This is a divide-by-zero vulnerability in the Linux kernel's AMD display driver. It occurs when a plane's viewport has zero area, causing a function to return zero values that lead to division by zero and potential underflow errors. The issue is fixed by changing the function to return a boolean and adding checks to prevent zero values.

Detection Guidance

This vulnerability is specific to the Linux kernel's AMD display driver. Detection requires checking kernel logs for divide-by-zero errors related to calculate_mcache_setting. Monitor system logs with commands like dmesg | grep -i divide or journalctl -k | grep -i divide. If such errors appear, the system is affected.

Impact Analysis

This vulnerability can cause system crashes due to divide-by-zero errors. It may also lead to display malfunctions or graphical corruption if the affected driver is used. Users relying on AMD graphics in the Linux kernel could experience system instability.

Compliance Impact

This vulnerability causes a divide-by-zero panic in the Linux kernel's AMD display driver, leading to system crashes. It does not directly affect data privacy or security controls required by GDPR or HIPAA, as it is a stability issue rather than a data exposure or access control flaw.

Mitigation Strategies

Update the Linux kernel to a patched version that includes the fix for this issue. Check your distribution's security advisories or kernel updates. If an update is unavailable, consider disabling the AMD display driver or using a different display driver as a temporary workaround.

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