From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751306AbdBXMMt (ORCPT ); Fri, 24 Feb 2017 07:12:49 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:56756 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751125AbdBXMMj (ORCPT ); Fri, 24 Feb 2017 07:12:39 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Eric Dumazet" , "David S. Miller" , "Andrey Konovalov" Date: Fri, 24 Feb 2017 12:10:01 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 11/12] dccp: fix freeing skb too early for IPV6_RECVPKTINFO In-Reply-To: X-SA-Exim-Connect-IP: 82.70.136.246 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.41-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Andrey Konovalov commit 5edabca9d4cff7f1f2b68f0bac55ef99d9798ba4 upstream. 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 Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/dccp/input.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -606,7 +606,8 @@ int dccp_rcv_state_process(struct sock * 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;