From: Konstantin Khlebnikov <koct9i@gmail.com>
Date: Sun, 31 Jan 2016 13:21:29 +0000 (+0300)
Subject: ovl: copy new uid/gid into overlayfs runtime inode
X-Git-Tag: firefly_0821_release~176^2~4^2~51^2~42
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b3600dd6476cd5ce390991860789163aa109f490;p=firefly-linux-kernel-4.4.55.git

ovl: copy new uid/gid into overlayfs runtime inode

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@gmail.com>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index b29036aa8d7c..05ac9a95e881 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -65,6 +65,8 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr)
 
 		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);