Executive brief
The AMD GPU driver in the Linux kernel failed to validate the size of indirect command buffers (IBs) submitted by users, allowing oversized values to corrupt control bits in packet encoding. An attacker with GPU access could craft malicious command submissions that destabilize GPU operations, potentially causing denial of service or enabling privilege escalation on systems using AMD graphics.
Technical details
The vulnerability exists in the amdgpu_cs_p2_ib() function, which accepted user-supplied ib_bytes values without enforcing per-ring packet size limits. When ring_emit_ib() encodes the length into packet fields using a 20-bit field for GFX/compute/SDMA/VPE rings, oversized values overflow and corrupt adjacent control bits, destabilizing command submission. The fix adds per-ring IB packet size limit validation before IB allocation, rejecting submissions exceeding 0xFFFFF dwords (GFX/compute/SDMA/VPE) or 0x7FFFF0 dwords (other ring types). Attack requires direct GPU access (local attack vector) and is present in the DRM/amdgpu subsystem of affected kernels.
Affected products
- Linux Linux kernel prior to fix commit 7f48fa2cf62e3fa6c9c3870aa74988f773247e52
Timeline
- 2026-08-26: disclosed: CVE-2026-80576 published
- 2026-08-23: patched: Fix committed to stable kernel trees