From de1ef4ffd70e1d15f0bf584fd22b1f28cbd5e2ec Mon Sep 17 00:00:00 2001 From: Junrui Luo Date: Tue, 24 Mar 2026 17:39:02 +0800 Subject: [PATCH] drm/amdgpu: validate doorbell_offset in user queue creation amdgpu_userq_get_doorbell_index() passes the user-provided doorbell_offset to amdgpu_doorbell_index_on_bar() without bounds checking. An arbitrarily large doorbell_offset can cause the calculated doorbell index to fall outside the allocated doorbell BO, potentially corrupting kernel doorbell space. Validate that doorbell_offset falls within the doorbell BO before computing the BAR index, using u64 arithmetic to prevent overflow. Fixes: f09c1e6077ab ("drm/amdgpu: generate doorbell index for userqueue") Reported-by: Yuhao Jiang Signed-off-by: Junrui Luo Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c index 7f64b783954ae..0d8f6bfc8d1db 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c @@ -600,6 +600,13 @@ amdgpu_userq_get_doorbell_index(struct amdgpu_userq_mgr *uq_mgr, goto unpin_bo; } + /* Validate doorbell_offset is within the doorbell BO */ + if ((u64)db_info->doorbell_offset * db_size + db_size > + amdgpu_bo_size(db_obj->obj)) { + r = -EINVAL; + goto unpin_bo; + } + index = amdgpu_doorbell_index_on_bar(uq_mgr->adev, db_obj->obj, db_info->doorbell_offset, db_size); drm_dbg_driver(adev_to_drm(uq_mgr->adev), -- 2.47.3