Executive brief
The AMD GPU driver in the Linux kernel contains a resource leak vulnerability in its command submission handler. An attacker can craft GPU commands with duplicate FENCE chunks that cause buffer object references to be leaked, potentially allowing denial-of-service attacks or resource exhaustion on systems using AMD GPUs.
Technical details
The amdgpu_cs_pass1() function in the AMD GPU command submission path fails to reject duplicate AMDGPU_CHUNK_ID_FENCE chunks within a single submission. The p->uf_bo field is a single-slot buffer object pointer; when duplicate FENCE chunks are submitted, amdgpu_cs_p1_user_fence() is invoked multiple times, with each iteration overwriting p->uf_bo with a new reference without releasing the previous one. Since amdgpu_cs_parser_fini() only unreferences the final p->uf_bo value, all but the last leaked reference persists beyond handle closure and process termination. The fix adds a simple check to reject subsequent FENCE chunks, mirroring the earlier BO_HANDLES chunk validation.
Affected products
- Linux Linux kernel v5.0 through v6.18 and later
Timeline
- 2026-08-26: disclosed
- 2026-08-23: patched