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

xen/gntdev: Fix partial gntdev_mmap() cleanup

to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: xen-gntdev-fix-partial-gntdev_mmap-cleanup.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 stable@vger.kernel.org know about it.

From foo@baz Wed Feb 28 16:16:23 CET 2018

From: Ross Lagerwall ross.lagerwall@citrix.com Date: Tue, 9 Jan 2018 12:10:22 +0000 Subject: xen/gntdev: Fix partial gntdev_mmap() cleanup

From: Ross Lagerwall ross.lagerwall@citrix.com

[ Upstream commit cf2acf66ad43abb39735568f55e1f85f9844e990 ]

When cleaning up after a partially successful gntdev_mmap(), unmap the successfully mapped grant pages otherwise Xen will kill the domain if in debug mode (Attempt to implicitly unmap a granted PTE) or Linux will kill the process and emit "BUG: Bad page map in process" if Xen is in release mode.

This is only needed when use_ptemod is true because gntdev_put_map() will unmap grant pages itself when use_ptemod is false.

Signed-off-by: Ross Lagerwall ross.lagerwall@citrix.com Reviewed-by: Boris Ostrovsky boris.ostrovsky@oracle.com Signed-off-by: Boris Ostrovsky boris.ostrovsky@oracle.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/xen/gntdev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -817,8 +817,10 @@ unlock_out: out_unlock_put: mutex_unlock(&priv->lock); out_put_map: - if (use_ptemod) + if (use_ptemod) { map->vma = NULL; + unmap_grant_pages(map, 0, map->count); + } gntdev_put_map(priv, map); return err; }

Patches currently in stable-queue which might be from ross.lagerwall@citrix.com are

queue-3.18/xen-gntdev-fix-off-by-one-error-when-unmapping-with-holes.patch queue-3.18/xen-gntdev-fix-partial-gntdev_mmap-cleanup.patch