linux-kernel - [PATCH 3.19.y-ckt 48/70] ovl: copy new uid/gid into overlayfs runtime inode

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Date:	Wed, 16 Mar 2016 13:05:41 -0700
From:	Kamal Mostafa <kamal@...onical.com>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com
Cc:	Konstantin Khlebnikov <koct9i@...il.com>,
	Miklos Szeredi <miklos@...redi.hu>,
	Kamal Mostafa <kamal@...onical.com>
Subject: [PATCH 3.19.y-ckt 48/70] ovl: copy new uid/gid into overlayfs runtime inode

v3.19.8-ckt17 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Konstantin Khlebnikov <koct9i@...il.com>

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@...il.com>
Signed-off-by: Miklos Szeredi <miklos@...redi.hu>
Signed-off-by: Kamal Mostafa <kamal@...onical.com>
---
 fs/overlayfs/inode.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 8525e67..e7a505c 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -55,6 +55,8 @@ 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);
-- 
2.7.0