NFS4: fix cb_recallany decode error

craa_type_mask is bitmap4 per RFC5661. We need to expect a length before
extracting bitmap value.

Cc: Alexandros Batsakis <batsakis@netapp.com>
Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 6 insertions, 5 deletions

diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
index 918ad647afea..ee1a5b3cd48d 100644
--- a/fs/nfs/callback_xdr.c
+++ b/fs/nfs/callback_xdr.c
@@ -488,17 +488,18 @@ static __be32 decode_recallany_args(struct svc_rqst *rqstp,
                                       struct xdr_stream *xdr,
                                       struct cb_recallanyargs *args)
 {
-        __be32 *p;
+        uint32_t bitmap[2];
+        __be32 *p, status;
 
         args->craa_addr = svc_addr(rqstp);
         p = read_buf(xdr, 4);
         if (unlikely(p == NULL))
                 return htonl(NFS4ERR_BADXDR);
         args->craa_objs_to_keep = ntohl(*p++);
-        p = read_buf(xdr, 4);
-        if (unlikely(p == NULL))
-                return htonl(NFS4ERR_BADXDR);
-        args->craa_type_mask = ntohl(*p);
+        status = decode_bitmap(xdr, bitmap);
+        if (unlikely(status))
+                return status;
+        args->craa_type_mask = bitmap[0];
 
         return 0;
 }