Patch "drm/vmwgfx: limit the number of mip levels in vmw_gb_surface_define_ioctl()" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

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

    drm/vmwgfx: limit the number of mip levels in vmw_gb_surface_define_ioctl()

to the 4.4-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-limit-the-number-of-mip-levels-in-vmw_gb_surface_define_ioctl.patch
and it can be found in the queue-4.4 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 ee9c4e681ec4f58e42a83cb0c22a0289ade1aacf Mon Sep 17 00:00:00 2001
From: Vladis Dronov <vdronov@redhat.com>
Date: Fri, 2 Jun 2017 07:42:09 +0200
Subject: drm/vmwgfx: limit the number of mip levels in vmw_gb_surface_define_ioctl()

From: Vladis Dronov <vdronov@redhat.com>

commit ee9c4e681ec4f58e42a83cb0c22a0289ade1aacf upstream.

The 'req->mip_levels' parameter in vmw_gb_surface_define_ioctl() is
a user-controlled 'uint32_t' value which is used as a loop count limit.
This can lead to a kernel lockup and DoS. Add check for 'req->mip_levels'.

References:
https://bugzilla.redhat.com/show_bug.cgi?id=1437431

Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/vmwgfx/vmwgfx_surface.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
@@ -1293,6 +1293,9 @@ int vmw_gb_surface_define_ioctl(struct d
 	if (req->multisample_count != 0)
 		return -EINVAL;
 
+	if (req->mip_levels > DRM_VMW_MAX_MIP_LEVELS)
+		return -EINVAL;
+
 	if (unlikely(vmw_user_surface_size == 0))
 		vmw_user_surface_size = ttm_round_pot(sizeof(*user_srf)) +
 			128;


Patches currently in stable-queue which might be from vdronov@redhat.com are

queue-4.4/drm-vmwgfx-limit-the-number-of-mip-levels-in-vmw_gb_surface_define_ioctl.patch