[NET]: Do not dereference iov if length is zero
When msg_iovlen is zero we shouldn't try to dereference
msg_iov. Right now the only thing that tries to do so
is skb_copy_and_csum_datagram_iovec. Since the total
length should also be zero if msg_iovlen is zero, it's
sufficient to check the total length there and simply
return if it's zero.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/datagram.c b/net/core/datagram.c
index cb056f4..029b93e 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -450,6 +450,9 @@
__wsum csum;
int chunk = skb->len - hlen;
+ if (!chunk)
+ return 0;
+
/* Skip filled elements.
* Pretty silly, look at memcpy_toiovec, though 8)
*/