CVE-2026-53285: drm/amd/display: Wrap DCN32 phantom-plane allocation in DC_RUN_WITH_PREEMPTION_ENABLED

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-26 · updated 2026-10-21
Weakness: CWE-617

Description

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Wrap DCN32 phantom-plane allocation in DC_RUN_WITH_PREEMPTION_ENABLED [Why] dcn32_validate_bandwidth() wraps dcn32_internal_validate_bw() with DC_FP_START()/DC_FP_END(). In x86 non-RT, DC_FP_START takes fpregs_lock(), which disables local softirqs. The DML1 path through dcn32_enable_phantom_plane() calls kvzalloc() to allocate ~335 KiB for dc_plane_state. This triggers the vmalloc path, which calls BUG_ON(in_interrupt()) because it's invoked within the FPU-enabled (softirq disabled) region, leading to a kernel crash. [How] Wrap the dc_state_create_phantom_plane() call with the DC_RUN_WITH_PREEMPTION_ENABLED() macro to allow preemption during this memory allocation. (cherry picked from commit 885ccbef7b94a8b38f69c4211c679021aa27ad11)

Affected products

Linux kernel: from 6.0 before 7.0.10; 7.1-rc1, 7.1-rc2, 7.1-rc3 — fixed in 7.0.10

How to fix

Upgrade to a fixed version: Linux kernel 7.0.10. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-53285 or the next vulnerability affects your stack