Patch "drm/msm: fix an integer overflow test" has been added to the 4.9-stable tree

Patch "drm/msm: fix an integer overflow test" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    drm/msm: fix an integer overflow test

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-msm-fix-an-integer-overflow-test.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 65e93108891e571f177c202add9288eda9ac4100 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Fri, 30 Jun 2017 10:59:15 +0300
Subject: drm/msm: fix an integer overflow test

From: Dan Carpenter <dan.carpenter@oracle.com>

commit 65e93108891e571f177c202add9288eda9ac4100 upstream.

We recently added an integer overflow check but it needs an additional
tweak to work properly on 32 bit systems.

The problem is that we're doing the right hand side of the assignment as
type unsigned long so the max it will have an integer overflow instead
of being larger than SIZE_MAX.  That means the "sz > SIZE_MAX" condition
is never true even on 32 bit systems.  We need to first cast it to u64
and then do the math.

Fixes: 4a630fadbb29 ("drm/msm: Fix potential buffer overflow issue")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-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 |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -34,8 +34,8 @@ static struct msm_gem_submit *submit_cre
 		struct msm_gpu *gpu, uint32_t nr_bos, uint32_t nr_cmds)
 {
 	struct msm_gem_submit *submit;
-	uint64_t sz = sizeof(*submit) + (nr_bos * sizeof(submit->bos[0])) +
-		(nr_cmds * sizeof(submit->cmd[0]));
+	uint64_t sz = sizeof(*submit) + ((u64)nr_bos * sizeof(submit->bos[0])) +
+		((u64)nr_cmds * sizeof(submit->cmd[0]));
 
 	if (sz > SIZE_MAX)
 		return NULL;


Patches currently in stable-queue which might be from dan.carpenter@oracle.com are

queue-4.9/drm-msm-fix-an-integer-overflow-test.patch