From: Weston Andros Adamson <dros@primarydata.com>
Date: Mon, 20 Jan 2014 03:45:36 +0000 (-0500)
Subject: nfs4: fix discover_server_trunking use after free
X-Git-Url: http://git.mmlx.us/?a=commitdiff_plain;h=daab6e7df44ba7d4281379c6ac5780e10d133286;p=linux-edison.git

nfs4: fix discover_server_trunking use after free

commit abad2fa5ba67725a3f9c376c8cfe76fbe94a3041 upstream.

If clp is new (cl_count = 1) and it matches another client in
nfs4_discover_server_trunking, the nfs_put_client will free clp before
->cl_preserve_clid is set.

Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
index 3afae905922..02773aab43c 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -240,13 +240,11 @@ struct nfs_client *nfs4_init_client(struct nfs_client *clp,
 	error = nfs4_discover_server_trunking(clp, &old);
 	if (error < 0)
 		goto error;
-	nfs_put_client(clp);
-	if (clp != old) {
-		clp->cl_preserve_clid = true;
-		clp = old;
-	}
 
-	return clp;
+	if (clp != old)
+		clp->cl_preserve_clid = true;
+	nfs_put_client(clp);
+	return old;
 
 error:
 	nfs_mark_client_ready(clp, error);