From 105f5528b9bbaa08b526d3405a5bcd2ff0c953c8 Mon Sep 17 00:00:00 2001 From: Jamie Bainbridge Date: Wed, 26 Apr 2017 10:43:27 +1000 Subject: ipv6: check raw payload size correctly in ioctl In situations where an skb is paged, the transport header pointer and tail pointer can be the same because the skb contents are in frags. This results in ioctl(SIOCINQ/FIONREAD) incorrectly returning a length of 0 when the length to receive is actually greater than zero. skb->len is already correctly set in ip6_input_finish() with pskb_pull(), so use skb->len as it always returns the correct result for both linear and paged data. Signed-off-by: Jamie Bainbridge Signed-off-by: David S. Miller --- net/ipv6/raw.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c index f174e76e6505..0da6a12b5472 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -1178,8 +1178,7 @@ static int rawv6_ioctl(struct sock *sk, int cmd, unsigned long arg) spin_lock_bh(&sk->sk_receive_queue.lock); skb = skb_peek(&sk->sk_receive_queue); if (skb) - amount = skb_tail_pointer(skb) - - skb_transport_header(skb); + amount = skb->len; spin_unlock_bh(&sk->sk_receive_queue.lock); return put_user(amount, (int __user *)arg); } -- cgit v1.2.3