In situations where an skb is paged, the transport header pointer and tail pointer will be the same because the payload is in skb frags.
This results in ioctl(SIOCINQ/FIONREAD) 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 <jbain...@redhat.com> --- 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 f174e76e6505d4045e940c9fceef765d2aaa937d..0da6a12b5472e322d679572c7244e5c9bc467741 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); } -- 1.8.3.1