[PATCH v2] drm/amdgpu: check a user-provided number of BOs in list

[Denis Arefev <arefev@swemel.ru>]

The user can set any value to the variable ‘bo_number’, via the ioctl
command DRM_IOCTL_AMDGPU_BO_LIST. This will affect the arithmetic
expression ‘in->bo_number * in->bo_info_size’, which is prone to
overflow. Add a valid value check.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 964d0fbf6301 ("drm/amdgpu: Allow to create BO lists in CS ioctl v3")
Cc: stable@vger.kernel.org
Signed-off-by: Denis Arefev <arefev@swemel.ru>
---
V1 -> V2:
Set a reasonable limit 'USHRT_MAX' for 'bo_number' it as Christian König <christian.koenig@amd.com> suggested

 drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
index 702f6610d024..85f7ee1e085d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
@@ -189,6 +189,9 @@ int amdgpu_bo_create_list_entry_array(struct drm_amdgpu_bo_list_in *in,
 	struct drm_amdgpu_bo_list_entry *info;
 	int r;
 
+	if (!in->bo_number || in->bo_number > USHRT_MAX)
+		return -EINVAL;
+
 	info = kvmalloc_array(in->bo_number, info_size, GFP_KERNEL);
 	if (!info)
 		return -ENOMEM;
-- 
2.43.0