Patch "drm/vmwgfx: Limit the user-space command buffer size" has been added to the 4.8-stable tree

Patch "drm/vmwgfx: Limit the user-space command buffer size" has been added to the 4.8-stable tree

[gregkh]

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

    drm/vmwgfx: Limit the user-space command buffer size

to the 4.8-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-user-space-command-buffer-size.patch
and it can be found in the queue-4.8 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 51ab70bed997f64f091a639dbe22b629725a7faf Mon Sep 17 00:00:00 2001
From: Thomas Hellstrom <thellstrom@vmware.com>
Date: Mon, 10 Oct 2016 10:51:24 -0700
Subject: drm/vmwgfx: Limit the user-space command buffer size

From: Thomas Hellstrom <thellstrom@vmware.com>

commit 51ab70bed997f64f091a639dbe22b629725a7faf upstream.

With older hardware versions, the user could specify arbitrarily large
command buffer sizes, causing a vmalloc / vmap space exhaustion.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
Signed-off-by: Sinclair Yeh <syeh@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
@@ -3848,14 +3848,14 @@ static void *vmw_execbuf_cmdbuf(struct v
 	int ret;
 
 	*header = NULL;
-	if (!dev_priv->cman || kernel_commands)
-		return kernel_commands;
-
 	if (command_size > SVGA_CB_MAX_SIZE) {
 		DRM_ERROR("Command buffer is too large.\n");
 		return ERR_PTR(-EINVAL);
 	}
 
+	if (!dev_priv->cman || kernel_commands)
+		return kernel_commands;
+
 	/* If possible, add a little space for fencing. */
 	cmdbuf_size = command_size + 512;
 	cmdbuf_size = min_t(size_t, cmdbuf_size, SVGA_CB_MAX_SIZE);


Patches currently in stable-queue which might be from thellstrom@vmware.com are

queue-4.8/drm-vmwgfx-limit-the-user-space-command-buffer-size.patch