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 X-Spam-Level: X-Spam-Status: No, score=-5.7 required=3.0 tests=DATE_IN_PAST_03_06, DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A30DBC33CAF for ; Wed, 22 Jan 2020 13:30:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 76490205F4 for ; Wed, 22 Jan 2020 13:30:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579699825; bh=Gf87LfOv9JacYdKcx/n23gu/OfWb61p8ecz42/mVdus=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0sev9U9n15u7ToUK/FqIGo/6D5zIOaGN2YG+zoL8M1OiLqan6l8ix9JqcpDQDqFBS gQcBMq4zbjeGFaEW+6eeGSQDZs3BjKZljRTmSHEe9Ww1nHkp9va+X6ZB17CKqGpbJr ymLPa1nukH8Fa0HdEyIaLjOxI0wJdAVPueRHlTs0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730319AbgAVNXT (ORCPT ); Wed, 22 Jan 2020 08:23:19 -0500 Received: from mail.kernel.org ([198.145.29.99]:41400 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729410AbgAVNXQ (ORCPT ); Wed, 22 Jan 2020 08:23:16 -0500 Received: from localhost (unknown [84.241.205.26]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1A4192468A; Wed, 22 Jan 2020 13:23:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579699395; bh=Gf87LfOv9JacYdKcx/n23gu/OfWb61p8ecz42/mVdus=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2gf7HW723E/WGLK0/iqQWcTzF37FtSH/7NxtMubrFpW5a2ETJhfqchfFkcowMQia4 wbArYcrWBVkLyfittLITpVhVtaKFyjyMmuJ1OWfyMg16uc9QWCh9SSRFIlK2byY93A TXtr7RBd9nzMOfByTKVqyysAfymBlPj1maCKn4aE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+37a6804945a3a13b1572@syzkaller.appspotmail.com, Florian Westphal , Pablo Neira Ayuso Subject: [PATCH 5.4 131/222] netfilter: nf_tables: fix flowtable list del corruption Date: Wed, 22 Jan 2020 10:28:37 +0100 Message-Id: <20200122092843.127326322@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200122092833.339495161@linuxfoundation.org> References: <20200122092833.339495161@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Florian Westphal commit 335178d5429c4cee61b58f4ac80688f556630818 upstream. syzbot reported following crash: list_del corruption, ffff88808c9bb000->prev is LIST_POISON2 (dead000000000122) [..] Call Trace: __list_del_entry include/linux/list.h:131 [inline] list_del_rcu include/linux/rculist.h:148 [inline] nf_tables_commit+0x1068/0x3b30 net/netfilter/nf_tables_api.c:7183 [..] The commit transaction list has: NFT_MSG_NEWTABLE NFT_MSG_NEWFLOWTABLE NFT_MSG_DELFLOWTABLE NFT_MSG_DELTABLE A missing generation check during DELTABLE processing causes it to queue the DELFLOWTABLE operation a second time, so we corrupt the list here: case NFT_MSG_DELFLOWTABLE: list_del_rcu(&nft_trans_flowtable(trans)->list); nf_tables_flowtable_notify(&trans->ctx, because we have two different DELFLOWTABLE transactions for the same flowtable. We then call list_del_rcu() twice for the same flowtable->list. The object handling seems to suffer from the same bug so add a generation check too and only queue delete transactions for flowtables/objects that are still active in the next generation. Reported-by: syzbot+37a6804945a3a13b1572@syzkaller.appspotmail.com Fixes: 3b49e2e94e6eb ("netfilter: nf_tables: add flow table netlink frontend") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman --- net/netfilter/nf_tables_api.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -981,12 +981,18 @@ static int nft_flush_table(struct nft_ct } list_for_each_entry_safe(flowtable, nft, &ctx->table->flowtables, list) { + if (!nft_is_active_next(ctx->net, flowtable)) + continue; + err = nft_delflowtable(ctx, flowtable); if (err < 0) goto out; } list_for_each_entry_safe(obj, ne, &ctx->table->objects, list) { + if (!nft_is_active_next(ctx->net, obj)) + continue; + err = nft_delobj(ctx, obj); if (err < 0) goto out;