From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrey Konovalov Subject: [PATCH] dccp: fix freeing skb too early for IPV6_RECVPKTINFO Date: Thu, 16 Feb 2017 17:22:46 +0100 Message-ID: <20170216162246.12783-1-andreyknvl@google.com> Cc: netdev@vger.kernel.org, Eric Dumazet , Gerrit Renker , Dmitry Vyukov , Kostya Serebryany , Alexander Potapenko , Andrey Konovalov To: "David S . Miller" Return-path: Received: from mail-wm0-f49.google.com ([74.125.82.49]:34903 "EHLO mail-wm0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932316AbdBPQXC (ORCPT ); Thu, 16 Feb 2017 11:23:02 -0500 Received: by mail-wm0-f49.google.com with SMTP id v186so70591861wmd.0 for ; Thu, 16 Feb 2017 08:23:01 -0800 (PST) Sender: netdev-owner@vger.kernel.org List-ID: 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: fb7e2399ec17f1004c0e0ccfd17439f8759ede01 [TCP]: skb is unexpectedly freed. 0aea76d35c9651d55bbaf746e7914e5f9ae5a25d tcp: SYN packets are now simply consumed Signed-off-by: Andrey Konovalov --- net/dccp/input.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/dccp/input.c b/net/dccp/input.c index ba347184bda9..8fedc2d49770 100644 --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -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; -- 2.11.0.483.g087da7b7c-goog