1 files changed, 11 insertions, 10 deletions

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 1750d996f49f..730ec8fb31c6 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -3355,7 +3355,7 @@ static int decode_readdir(struct xdr_stream *xdr, struct rpc_rqst *req, struct n
         struct kvec     *iov = rcvbuf->head;
         unsigned int    nr, pglen = rcvbuf->page_len;
         uint32_t        *end, *entry, *p, *kaddr;
-        uint32_t        len, attrlen;
+        uint32_t        len, attrlen, xlen;
         int             hdrlen, recvd, status;
 
         status = decode_op_hdr(xdr, OP_READDIR);
@@ -3377,10 +3377,10 @@ static int decode_readdir(struct xdr_stream *xdr, struct rpc_rqst *req, struct n
 
         BUG_ON(pglen + readdir->pgbase > PAGE_CACHE_SIZE);
         kaddr = p = (uint32_t *) kmap_atomic(page, KM_USER0);
-        end = (uint32_t *) ((char *)p + pglen + readdir->pgbase);
+        end = p + ((pglen + readdir->pgbase) >> 2);
         entry = p;
         for (nr = 0; *p++; nr++) {
-                if (p + 3 > end)
+                if (end - p < 3)
                         goto short_pkt;
                 dprintk("cookie = %Lu, ", *((unsigned long long *)p));
                 p += 2;                 /* cookie */
@@ -3389,18 +3389,19 @@ static int decode_readdir(struct xdr_stream *xdr, struct rpc_rqst *req, struct n
                         printk(KERN_WARNING "NFS: giant filename in readdir (len 0x%x)\n", len);
                         goto err_unmap;
                 }
-                dprintk("filename = %*s\n", len, (char *)p);
-                p += XDR_QUADLEN(len);
-                if (p + 1 > end)
+                xlen = XDR_QUADLEN(len);
+                if (end - p < xlen + 1)
                         goto short_pkt;
+                dprintk("filename = %*s\n", len, (char *)p);
+                p += xlen;
                 len = ntohl(*p++);      /* bitmap length */
-                p += len;
-                if (p + 1 > end)
+                if (end - p < len + 1)
                         goto short_pkt;
+                p += len;
                 attrlen = XDR_QUADLEN(ntohl(*p++));
-                p += attrlen;           /* attributes */
-                if (p + 2 > end)
+                if (end - p < attrlen + 2)
                         goto short_pkt;
+                p += attrlen;           /* attributes */
                 entry = p;
         }
         if (!nr && (entry[0] != 0 || entry[1] == 0))