[PATCH] RPC: fix accounting bug in the case of a truncated RPC message

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

1 files changed, 14 insertions, 8 deletions

diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index 65b268d39782..b3ac3f72bf9c 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -176,21 +176,23 @@ xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset,
         xdr->buflen += len;
 }
 
-int
+ssize_t
 xdr_partial_copy_from_skb(struct xdr_buf *xdr, unsigned int base,
                           skb_reader_t *desc,
                           skb_read_actor_t copy_actor)
 {
         struct page     **ppage = xdr->pages;
         unsigned int    len, pglen = xdr->page_len;
+        ssize_t         copied = 0;
         int             ret;
 
         len = xdr->head[0].iov_len;
         if (base < len) {
                 len -= base;
                 ret = copy_actor(desc, (char *)xdr->head[0].iov_base + base, len);
+                copied += ret;
                 if (ret != len || !desc->count)
-                        return 0;
+                        goto out;
                 base = 0;
         } else
                 base -= len;
@@ -214,8 +216,11 @@ xdr_partial_copy_from_skb(struct xdr_buf *xdr, unsigned int base,
                  * are small by default but can get huge. */
                 if (unlikely(*ppage == NULL)) {
                         *ppage = alloc_page(GFP_ATOMIC);
-                        if (unlikely(*ppage == NULL))
-                                return -ENOMEM;
+                        if (unlikely(*ppage == NULL)) {
+                                if (copied == 0)
+                                        copied = -ENOMEM;
+                                goto out;
+                        }
                 }
 
                 len = PAGE_CACHE_SIZE;
@@ -233,16 +238,17 @@ xdr_partial_copy_from_skb(struct xdr_buf *xdr, unsigned int base,
                 }
                 flush_dcache_page(*ppage);
                 kunmap_atomic(kaddr, KM_SKB_SUNRPC_DATA);
+                copied += ret;
                 if (ret != len || !desc->count)
-                        return 0;
+                        goto out;
                 ppage++;
         } while ((pglen -= len) != 0);
 copy_tail:
         len = xdr->tail[0].iov_len;
         if (base < len)
-                copy_actor(desc, (char *)xdr->tail[0].iov_base + base, len - base);
-
-        return 0;
+                copied += copy_actor(desc, (char *)xdr->tail[0].iov_base + base, len - base);
+out:
+        return copied;
 }