From: Kasin Li <donglil@codeaurora.org>
Date: Mon, 19 Jun 2017 21:36:53 +0000 (-0600)
Subject: drm/msm: Fix potential buffer overflow issue
X-Git-Tag: v3.18.80~17
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f449835963f47a3755d2f893a49928cf8d7ca58e;p=thirdparty%2Fkernel%2Fstable.git

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 4a45ae01cc3ee..8acdb8192d206 100644
--- 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) {