drm/msm: Fix potential buffer overflow issue

commit 4a630fadbb29d9efaedb525f1a8f7449ad107641 upstream.

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>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index fed44d4e5b7298281b45b238f9ef2e1592b3d8fe..34edb4a4ccd49dabfdc4011138ad01a00827c762 100644 (file)
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -34,10 +34,13 @@ static inline void __user *to_user_ptr(u64 address)
 }
 
 static struct msm_gem_submit *submit_create(struct drm_device *dev,
-               struct msm_gpu *gpu, int nr)
+               struct msm_gpu *gpu, uint32_t nr)
 {
        struct msm_gem_submit *submit;
-       int sz = sizeof(*submit) + (nr * sizeof(submit->bos[0]));
+       uint64_t sz = sizeof(*submit) + (nr * sizeof(submit->bos[0]));
+
+       if (sz > SIZE_MAX)
+               return NULL;
 
        submit = kmalloc(sz, GFP_TEMPORARY | __GFP_NOWARN | __GFP_NORETRY);
        if (submit) {