From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90C6EC433F5 for ; Thu, 19 May 2022 22:02:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245402AbiESWCe (ORCPT ); Thu, 19 May 2022 18:02:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46698 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242204AbiESWCV (ORCPT ); Thu, 19 May 2022 18:02:21 -0400 Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id CC773F68BC; Thu, 19 May 2022 15:02:19 -0700 (PDT) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org, pabeni@redhat.com Subject: [PATCH net-next 10/11] netfilter: cttimeout: fix slab-out-of-bounds read in cttimeout_net_exit Date: Fri, 20 May 2022 00:02:05 +0200 Message-Id: <20220519220206.722153-11-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220519220206.722153-1-pablo@netfilter.org> References: <20220519220206.722153-1-pablo@netfilter.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Florian Westphal syzbot reports: BUG: KASAN: slab-out-of-bounds in __list_del_entry_valid+0xcc/0xf0 lib/list_debug.c:42 [..] list_del include/linux/list.h:148 [inline] cttimeout_net_exit+0x211/0x540 net/netfilter/nfnetlink_cttimeout.c:617 No reproducer so far. Looking at recent changes in this area its clear that the free_head must not be at the end of the structure because nf_ct_timeout structure has variable size. Reported-by: Fixes: 78222bacfca9 ("netfilter: cttimeout: decouple unlink and free on netns destruction") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nfnetlink_cttimeout.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nfnetlink_cttimeout.c b/net/netfilter/nfnetlink_cttimeout.c index f069c24c6146..af15102bc696 100644 --- a/net/netfilter/nfnetlink_cttimeout.c +++ b/net/netfilter/nfnetlink_cttimeout.c @@ -35,12 +35,13 @@ static unsigned int nfct_timeout_id __read_mostly; struct ctnl_timeout { struct list_head head; + struct list_head free_head; struct rcu_head rcu_head; refcount_t refcnt; char name[CTNL_TIMEOUT_NAME_MAX]; - struct nf_ct_timeout timeout; - struct list_head free_head; + /* must be at the end */ + struct nf_ct_timeout timeout; }; struct nfct_timeout_pernet { -- 2.30.2