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://drtracing.org/?a=commitdiff_plain;h=abad2fa5ba67725a3f9c376c8cfe76fbe94a3041;p=deliverable%2Flinux.git

nfs4: fix discover_server_trunking use after free

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.

Cc: stable@vger.kernel.org # 3.7+
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
---

diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
index 06e770ace073..73d4ecda1e36 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -414,13 +414,11 @@ 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);