Commit 5edabca9 authored Feb 16, 2017 by Andrey Konovalov Committed by David S. Miller Feb 17, 2017

dccp: fix freeing skb too early for IPV6_RECVPKTINFO



In the current DCCP implementation an skb for a DCCP_PKT_REQUEST packet
is forcibly freed via __kfree_skb in dccp_rcv_state_process if
dccp_v6_conn_request successfully returns.

However, if IPV6_RECVPKTINFO is set on a socket, the address of the skb
is saved to ireq->pktopts and the ref count for skb is incremented in
dccp_v6_conn_request, so skb is still in use. Nevertheless, it gets freed
in dccp_rcv_state_process.

Fix by calling consume_skb instead of doing goto discard and therefore
calling __kfree_skb.

Similar fixes for TCP:

fb7e2399 [TCP]: skb is unexpectedly freed.
0aea76d3 tcp: SYN packets are now
simply consumed

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 785f3577

net/dccp/input.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -606,7 +606,8 @@ int dccp_rcv_state_process(struct sock sk, struct sk_buff skb,
		if (inet_csk(sk)->icsk_af_ops->conn_request(sk,
		skb) < 0)
		return 1;
		goto discard;
		consume_skb(skb);
		return 0;
		}
		if (dh->dccph_type == DCCP_PKT_RESET)
		goto discard;

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