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>

diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index 179cfc6..6bfca74 100644 (file)
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/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)