From bbaded590e3293abbbca4d58a8fb7ad8447b2640 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Thu, 20 Sep 2007 12:41:36 -0700 Subject: [PATCH] Fix datagram recvmsg NULL iov handling regression. commit ef8aef55ce61fd0e2af798695f7386ac756ae1e7 in mainline Subject: [PATCH] [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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/datagram.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/core/datagram.c b/net/core/datagram.c index cb056f476126..029b93e246b4 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -450,6 +450,9 @@ int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb, __wsum csum; int chunk = skb->len - hlen; + if (!chunk) + return 0; + /* Skip filled elements. * Pretty silly, look at memcpy_toiovec, though 8) */ -- 2.39.5