net: Fix off-by-one in skb_dma_map

The unwind loop iterates down to -1 instead of stopping at 0 and ends up
accessing ->frags[-1].

Signed-off-by: Dimitris Michailidis <dm@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/net/core/skb_dma_map.c b/net/core/skb_dma_map.c
index 1f49afcd8e86..86234923a3b7 100644
--- a/net/core/skb_dma_map.c
+++ b/net/core/skb_dma_map.c
@@ -35,7 +35,7 @@ int skb_dma_map(struct device *dev, struct sk_buff *skb,
         return 0;
 
 unwind:
-        while (i-- >= 0) {
+        while (--i >= 0) {
                 skb_frag_t *fp = &sp->frags[i];
 
                 dma_unmap_page(dev, sp->dma_maps[i + 1],