From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933267AbaKSVBa (ORCPT ); Wed, 19 Nov 2014 16:01:30 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:56371 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933195AbaKSVBU (ORCPT ); Wed, 19 Nov 2014 16:01:20 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Houcheng Lin , Florian Westphal , Pablo Neira Ayuso Subject: [PATCH 3.17 125/141] netfilter: nf_log: release skbuff on nlmsg put failure Date: Wed, 19 Nov 2014 12:52:28 -0800 Message-Id: <20141119205154.915892626@linuxfoundation.org> X-Mailer: git-send-email 2.1.3 In-Reply-To: <20141119205150.700188369@linuxfoundation.org> References: <20141119205150.700188369@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Houcheng Lin commit b51d3fa364885a2c1e1668f88776c67c95291820 upstream. The kernel should reserve enough room in the skb so that the DONE message can always be appended. However, in case of e.g. new attribute erronously not being size-accounted for, __nfulnl_send() will still try to put next nlmsg into this full skbuf, causing the skb to be stuck forever and blocking delivery of further messages. Fix issue by releasing skb immediately after nlmsg_put error and WARN() so we can track down the cause of such size mismatch. [ fw@strlen.de: add tailroom/len info to WARN ] Signed-off-by: Houcheng Lin Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman --- net/netfilter/nfnetlink_log.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -346,26 +346,25 @@ nfulnl_alloc_skb(struct net *net, u32 pe return skb; } -static int +static void __nfulnl_send(struct nfulnl_instance *inst) { - int status = -1; - if (inst->qlen > 1) { struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0, NLMSG_DONE, sizeof(struct nfgenmsg), 0); - if (!nlh) + if (WARN_ONCE(!nlh, "bad nlskb size: %u, tailroom %d\n", + inst->skb->len, skb_tailroom(inst->skb))) { + kfree_skb(inst->skb); goto out; + } } - status = nfnetlink_unicast(inst->skb, inst->net, inst->peer_portid, - MSG_DONTWAIT); - + nfnetlink_unicast(inst->skb, inst->net, inst->peer_portid, + MSG_DONTWAIT); +out: inst->qlen = 0; inst->skb = NULL; -out: - return status; } static void