From: Ross Lagerwall Date: Tue, 9 Jan 2018 12:10:22 +0000 (+0000) Subject: xen/gntdev: Fix partial gntdev_mmap() cleanup X-Git-Tag: v4.4.120~4 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=041250d9c35afde56628f11c4ed6d59d701b0b4c;p=thirdparty%2Fkernel%2Fstable.git xen/gntdev: Fix partial gntdev_mmap() cleanup [ 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 Reviewed-by: Boris Ostrovsky Signed-off-by: Boris Ostrovsky Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 44a9d8eb0eb4f..1865bcfa869bf 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -874,8 +874,10 @@ 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; }