linux-kernel - [PATCH] ovl: copy new uid/gid into overlayfs runtime inode

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Date:	Sun, 31 Jan 2016 16:21:29 +0300
From:	Konstantin Khlebnikov <koct9i@...il.com>
To:	linux-fsdevel@...r.kernel.org, linux-unionfs@...r.kernel.org,
	Miklos Szeredi <miklos@...redi.hu>
Cc:	linux-kernel@...r.kernel.org,
	Alexander Viro <viro@...iv.linux.org.uk>
Subject: [PATCH] ovl: copy new uid/gid into overlayfs runtime inode

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@...il.com>
---
 fs/overlayfs/inode.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 49e204560655..a4ff5d0d7db9 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -65,6 +65,8 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr)
 
 		inode_lock(upperdentry->d_inode);
 		err = notify_change(upperdentry, attr, NULL);
+		if (!err)
+			ovl_copyattr(upperdentry->d_inode, dentry->d_inode);
 		inode_unlock(upperdentry->d_inode);
 	}
 	ovl_drop_write(dentry);