# DF-1899 VERDICT

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

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

**Mechanism:** amdgpu_amdkfd_is_kfd_vmid L517 if((1<<vmid)&compute_vmid_bitmap) literal 1 is signed int; int<<int with shift>=32 is UB. No upper-bound check vmid (u32). On x86 shl masks count mod 32 so vmid 40/72/et

**Citation:** `sys/dev/drm/amd/amdgpu/amdgpu_amdkfd.c:514-522`

**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.