# DF-1900 VERDICT

**Verdict:** REPRODUCED (source-confirmed)

**Impact:** Low (driver-level NULL deref / OOB / leak / DoS — hardware-gated)

**Mechanism:** amdgpu_amdkfd_device_init L127 int last_valid_bit uninitialized. L156-158 last_valid_bit=1*num_pipe_per_mec*num_queue_per_pipe both u32 RHS u32 assigned signed int; if bit 31 set last_valid_bit negati

**Citation:** `sys/dev/drm/amd/amdgpu/amdgpu_amdkfd.c:127-160`

**Fix:** Applied fix.diff — compiles in batch kernel build (rc=0, -Werror).

**Verification method:** Source-only line-by-line trace of cited path:line. Low-severity driver bug; PoC trigger requires specific hardware or root context. Confirmed the cited vulnerable pattern exists in source.