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 3afae90..02773aa 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -240,13 +240,11 @@
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);