drm/amdgpu: Fix possible NULL dereference in amdgpu_ras_query_error_status_helper()

commit b8d55a90 upstream.

Return invalid error code -EINVAL for invalid block id.

Fixes the below:

drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c:1183 amdgpu_ras_query_error_status_helper() error: we previously assumed 'info' could be null (see line 1176)

Suggested-by: Hawking Zhang <Hawking.Zhang@amd.com>
Cc: Tao Zhou <tao.zhou1@amd.com>
Cc: Hawking Zhang <Hawking.Zhang@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Ajay: applied AMDGPU_RAS_BLOCK_COUNT condition to amdgpu_ras_error_query()
       as amdgpu_ras_query_error_status_helper() not present in v5.10, v5.4
       amdgpu_ras_query_error_status_helper() was introduced in 8cc0f566]
Signed-off-by: Ajay Kaher <ajay.kaher@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c

@@ -765,6 +765,9 @@ int amdgpu_ras_error_query(struct amdgpu_device *adev,
 	if (!obj)
 		return -EINVAL;
 
+	if (!info || info->head.block == AMDGPU_RAS_BLOCK_COUNT)
+		return -EINVAL;
+
 	switch (info->head.block) {
 	case AMDGPU_RAS_BLOCK__UMC:
 		if (adev->umc.funcs->query_ras_error_count)