4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx> [ 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@xxxxxxxxxx> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/xen/gntdev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -1077,8 +1077,10 @@ 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; }