[PATCH net 1/3] unix/dgram: peek beyond 0-sized skbs

Benjamin Poirier
2013-04-25T13:47:16Z

"77c1090 net: fix infinite loop in __skb_recv_datagram()" (v3.8) introduced a
regression:
After that commit, recv can no longer peek beyond a 0-sized skb in the queue.
__skb_recv_datagram() instead stops at the first skb with len == 0 and results
in the system call failing with -EFAULT via skb_copy_datagram_iovec().

Signed-off-by: Benjamin Poirier <bpoirier@suse.de>
---
net/core/datagram.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/datagram.c b/net/core/datagram.c
index 368f9c3..02398ae 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -187,7 +187,7 @@ struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned int flags,
skb_queue_walk(queue, skb) {
*peeked = skb->peeked;
if (flags & MSG_PEEK) {
- if (*off >= skb->len && skb->len) {
+ if (*off >= skb->len && (skb->len || *off)) {
*off -= skb->len;
continue;
}
--
1.7.10.4