NFSv4: Fix up decode_attr_filehandle() to handle the case of empty fh pointer

decode_attr_filehandle still needs to skip the XDR-encoded filehandle if
someone passes a null pointer argument.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 6 insertions, 8 deletions

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index ccfb1c92b262..a6b00e84bd1a 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -2883,12 +2883,8 @@ static int decode_attr_filehandle(struct xdr_stream *xdr, uint32_t *bitmap, stru
         __be32 *p;
         int len;
 
-        if (fh == NULL) {
-                bitmap[0] &= ~FATTR4_WORD0_FILEHANDLE;
-                return 0;
-        }
-
-        memset(fh, 0, sizeof(*fh));
+        if (fh != NULL)
+                memset(fh, 0, sizeof(*fh));
 
         if (unlikely(bitmap[0] & (FATTR4_WORD0_FILEHANDLE - 1U)))
                 return -EIO;
@@ -2899,11 +2895,13 @@ static int decode_attr_filehandle(struct xdr_stream *xdr, uint32_t *bitmap, stru
                 len = be32_to_cpup(p);
                 if (len > NFS4_FHSIZE)
                         return -EIO;
-                fh->size = len;
                 p = xdr_inline_decode(xdr, len);
                 if (unlikely(!p))
                         goto out_overflow;
-                memcpy(fh->data, p, len);
+                if (fh != NULL) {
+                        memcpy(fh->data, p, len);
+                        fh->size = len;
+                }
                 bitmap[0] &= ~FATTR4_WORD0_FILEHANDLE;
         }
         return 0;