CVE-2026-64219: drm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async

Severity: high (CVSS 7.0 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-24 · updated 2026-10-19
Weakness: CWE-674

Description

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async [Why&How] dc_process_dmub_aux_transfer_async() copies payload->length bytes into a 16-byte stack buffer (dpaux.data[16]) guarded only by an ASSERT(), which is a no-op in release builds. If a caller ever passes length > 16 this results in a stack buffer overflow via memcpy. Additionally, link_index is used to dereference dc->links[] without bounds checking against dc->link_count, risking an out-of-bounds access. Replace the ASSERT with a hard runtime check that returns false when payload->length exceeds the destination buffer size, and add a bounds check for link_index before it is used. (cherry picked from commit ba4caa9fecdf7a38f98c878ad05a8a64148b6881)

Affected products

Linux kernel: from 5.13 before 5.15.209; from 5.16 before 6.1.175; from 6.2 before 6.6.142; from 6.7 before 6.12.92; from 6.13 before 6.18.34; from 6.19 before 7.0.11 — fixed in 5.15.209, 6.1.175, 6.12.92, 6.18.34, 6.6.142, 7.0.11

How to fix

Upgrade to a fixed version: Linux kernel 5.15.209, 6.1.175, 6.12.92, 6.18.34. Check the vendor advisory for mitigations.

References

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