CVE-2026-46220
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk2th percentile - higher than 2% of all known CVEs
Summary
A vulnerability in the Linux kernel has been resolved by replacing BUG_ON() calls in the sdma_v4_0_ring_emit_fence() function with WARN_ON() calls. This allowed unprivileged users to trigger a kernel panic through misaligned fence writeback addresses.
Risk Assessment
This vulnerability poses a risk of critical system failures, potentially leading to downtime and data loss. Allowing unprivileged users to trigger a kernel panic represents a significant threat to system stability.
Recommendation
It is recommended to update the Linux kernel to the latest version to mitigate this vulnerability. Additionally, monitoring and filtering invalid submissions in the CS IOCTL path should be implemented.
Original NVD description (English source)
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)