CVE-2026-46220

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

drm/amdgpu/sdma4: replace BUG_ON with WARN_ON in fence emission

sdma_v4_0_ring_emit_fence() contains two BUG_ON(addr & 0x3) assertions

that verify fence writeback addresses are dword-aligned. These

assertions can be reached from unprivileged userspace via crafted

DRM_IOCTL_AMDGPU_CS submissions, causing a fatal kernel panic in a

scheduler worker thread.

Replace both BUG_ON() calls with WARN_ON() to log the condition without

crashing the kernel. A misaligned fence address at this point indicates

a driver bug, but crashing the kernel is never the correct response when

the assertion is reachable from userspace.

The CS IOCTL path is the correct place to filter invalid submissions;

the ring emission callback is too late to do anything about it.

(cherry picked from commit b90250bd933afd1ba94d86d6b13821997b22b18e)

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References