[PATCH 4.4 44/50] ovl: copy new uid/gid into overlayfs runtime inode

From: Greg Kroah-Hartman
Date: Mon Mar 14 2016 - 14:10:13 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Konstantin Khlebnikov <koct9i@xxxxxxxxx>

commit b81de061fa59f17d2730aabb1b84419ef3913810 upstream.

Overlayfs must update uid/gid after chown, otherwise functions
like inode_owner_or_capable() will check user against stale uid.
Catched by xfstests generic/087, it chowns file and calls utimes.

Signed-off-by: Konstantin Khlebnikov <koct9i@xxxxxxxxx>
Signed-off-by: Miklos Szeredi <miklos@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/overlayfs/inode.c | 2 ++
1 file changed, 2 insertions(+)

--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -65,6 +65,8 @@ int ovl_setattr(struct dentry *dentry, s

mutex_lock(&upperdentry->d_inode->i_mutex);
err = notify_change(upperdentry, attr, NULL);
+ if (!err)
+ ovl_copyattr(upperdentry->d_inode, dentry->d_inode);
mutex_unlock(&upperdentry->d_inode->i_mutex);
}
ovl_drop_write(dentry);