drm/msm: Fix potential buffer overflow issue

In function submit_create, if nr_cmds or nr_bos is assigned with
negative value, the allocated buffer may be small than intended.
Using this buffer will lead to buffer overflow issue.
Signed-off-by: Kasin Li <donglil@codeaurora.org>
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/msm_gem_submit.c

@@ -31,11 +31,14 @@
 #define BO_PINNED   0x2000
 
 static struct msm_gem_submit *submit_create(struct drm_device *dev,
-		struct msm_gpu *gpu, int nr_bos, int nr_cmds)
+		struct msm_gpu *gpu, uint32_t nr_bos, uint32_t nr_cmds)
 {
 	struct msm_gem_submit *submit;
-	int sz = sizeof(*submit) + (nr_bos * sizeof(submit->bos[0])) +
-			(nr_cmds * sizeof(*submit->cmd));
+	uint64_t sz = sizeof(*submit) + (nr_bos * sizeof(submit->bos[0])) +
+		(nr_cmds * sizeof(submit->cmd[0]));
+
+	if (sz > SIZE_MAX)
+		return NULL;
 
 	submit = kmalloc(sz, GFP_TEMPORARY | __GFP_NOWARN | __GFP_NORETRY);
 	if (!submit)