Patch "drm/vmwgfx: fix integer overflow in vmw_surface_define_ioctl()" has been added to the 3.18-stable tree

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

drm/vmwgfx: fix integer overflow in vmw_surface_define_ioctl()

to the 3.18-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-vmwgfx-fix-integer-overflow-in-vmw_surface_define_ioctl.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Li Qiang <[email protected]>
Date: Mon, 27 Mar 2017 20:10:53 -0700
Subject: drm/vmwgfx: fix integer overflow in vmw_surface_define_ioctl()

From: Li Qiang <[email protected]>

commit e7e11f99564222d82f0ce84bd521e57d78a6b678 upstream.

In vmw_surface_define_ioctl(), the 'num_sizes' is the sum of the 'req->mip_levels' array. This array can be assigned any value from the user space. As both the 'num_sizes' and the array is uint32_t, it is easy to make 'num_sizes' overflow. The later 'mip_levels' is used as the loop count. This can lead an oob write. Add the check of 'req->mip_levels' to avoid this.

---
 drivers/gpu/drm/vmwgfx/vmwgfx_surface.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

@@ -708,8 +708,11 @@ int vmw_surface_define_ioctl(struct drm_
 			128;
 
 	num_sizes = 0;
-	for (i = 0; i < DRM_VMW_MAX_SURFACE_FACES; ++i)
+	for (i = 0; i < DRM_VMW_MAX_SURFACE_FACES; ++i) {
+		if (req->mip_levels[i] > DRM_VMW_MAX_MIP_LEVELS)
+			return -EINVAL;
 		num_sizes += req->mip_levels[i];
+	}
 
 	if (num_sizes > DRM_VMW_MAX_SURFACE_FACES * DRM_VMW_MAX_MIP_LEVELS ||
 	    num_sizes == 0)

Patches currently in stable-queue which might be from [email protected] are

queue-3.18/drm-vmwgfx-fix-integer-overflow-in-vmw_surface_define_ioctl.patch