linux-kernel - [084/129] statfs() gives ESTALE error

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20100918191304.542135345@clark.site>
Date:	Sat, 18 Sep 2010 12:13:02 -0700
From:	Greg KH <gregkh@...e.de>
To:	linux-kernel@...r.kernel.org, stable@...nel.org
Cc:	stable-review@...nel.org, torvalds@...ux-foundation.org,
	akpm@...ux-foundation.org, alan@...rguk.ukuu.org.uk,
	Zoltan Menyhart <Zoltan.Menyhart@...l.net>,
	Trond Myklebust <Trond.Myklebust@...app.com>
Subject: [084/129] statfs() gives ESTALE error

2.6.35-stable review patch.  If anyone has any objections, please let us know.

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

From: Menyhart Zoltan <Zoltan.Menyhart@...l.net>

commit fbf3fdd2443965d9ba6fb4b5fecd1f6e0847218f upstream.

Hi,

An NFS client executes a statfs("file", &buff) call.
"file" exists / existed, the client has read / written it,
but it has already closed it.

user_path(pathname, &path) looks up "file" successfully in the
directory-cache  and restarts the aging timer of the directory-entry.
Even if "file" has already been removed from the server, because the
lookupcache=positive option I use, keeps the entries valid for a while.

nfs_statfs() returns ESTALE if "file" has already been removed from the
server.

If the user application repeats the statfs("file", &buff) call, we
are stuck: "file" remains young forever in the directory-cache.

Signed-off-by: Zoltan Menyhart  <Zoltan.Menyhart@...l.net>
Signed-off-by: Trond Myklebust <Trond.Myklebust@...app.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>

---
 fs/nfs/super.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -431,7 +431,15 @@ static int nfs_statfs(struct dentry *den
 		goto out_err;

 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
+	if (unlikely(error == -ESTALE)) {
+		struct dentry *pd_dentry;

+		pd_dentry = dget_parent(dentry);
+		if (pd_dentry != NULL) {
+			nfs_zap_caches(pd_dentry->d_inode);
+			dput(pd_dentry);
+		}
+	}
 	nfs_free_fattr(res.fattr);
 	if (error < 0)
 		goto out_err;

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/