NFSv4: handle lack of clientaddr in option string

If a NFSv4 mount is attempted  with string based options, and the
option string doesn't contain a clientaddr= option, the kernel will
currently oops. Check for this situation and return a proper error.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index adffe1615c51..b34b7a711d5b 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -1685,6 +1685,9 @@ static int nfs4_validate_mount_data(struct nfs4_mount_data **options,
 
                 dprintk("MNTPATH: %s\n", *mntpath);
 
+                if (args.client_address == NULL)
+                        goto out_no_client_address;
+
                 *ip_addr = args.client_address;
 
                 break;
@@ -1705,6 +1708,10 @@ out_inval_auth:
 out_no_address:
         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
         return -EINVAL;
+
+out_no_client_address:
+        dfprintk(MOUNT, "NFS4: mount program didn't pass callback address\n");
+        return -EINVAL;
 }
 
 /*