| From | Jiri Slaby <> | Subject | [PATCH 3.12 75/86] ipv6: check raw payload size correctly in ioctl | Date | Thu, 4 May 2017 11:04:40 +0200 |
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From: Jamie Bainbridge <jbainbri@redhat.com>
3.12-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 105f5528b9bbaa08b526d3405a5bcd2ff0c953c8 ]
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 <jbainbri@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> --- 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 c2afb29dc1d7..581662201ba9 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -1145,8 +1145,7 @@ 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 != NULL) - 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); } -- 2.12.2
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