[PATCH 3.18 11/27] drm/msm: Fix potential buffer overflow issue

Greg Kroah-Hartman
2017-11-06T11:29:10Z

From: Kasin Li <donglil@codeaurora.org>

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>

---
drivers/gpu/drm/msm/msm_gem_submit.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

--- 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(u
}

static struct msm_gem_submit *submit_create(struct drm_device *dev,
- struct msm_gpu *gpu, int nr)
+ struct msm_gpu *gpu, uint32_t int 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) {