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=-6.8 required=3.0 tests=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=unavailable 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 C05B0C33CB6 for ; Wed, 22 Jan 2020 09:44:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9731924689 for ; Wed, 22 Jan 2020 09:44:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579686246; bh=rVJI2B7s0TkvnPgK88jbbqnZPiY23Oy5Ei43rY+97l4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mENikJvXzfwklnVgbMZFfTwL9H5Hy9bZnwIsbFKWI9KdKLDnCJlACI1jE3e74dDEL F6TUypqqNb7OctrcYhuzDbIQXFdNGBTPsNdpYfs8E2CWl8GcWwy9MUoFLPcECMet0Q sXSvg7zW+DXGB6JiQbKJLJnDTMgvGc/mhDERPpwQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387989AbgAVJoF (ORCPT ); Wed, 22 Jan 2020 04:44:05 -0500 Received: from mail.kernel.org ([198.145.29.99]:36844 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387967AbgAVJn7 (ORCPT ); Wed, 22 Jan 2020 04:43:59 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 6E90724689; Wed, 22 Jan 2020 09:43:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579686238; bh=rVJI2B7s0TkvnPgK88jbbqnZPiY23Oy5Ei43rY+97l4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Plbff4TKu/gyO1hl2dJa4fdtakfzlUddjyr4fD/MWPvjLrYFP+2nEAUzRXoO0I/29 hfYgZmQAn9B3rS+qGieeoo+svOBx8FY9FY/gxNYRa31F3V5BtTfvQJmiNZKEtkaaum iGAn5DcLk7bgH2KuyIKG+oa2oLZZ300kfHB+AAOw= 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 4.19 064/103] netfilter: nf_tables: fix flowtable list del corruption Date: Wed, 22 Jan 2020 10:29:20 +0100 Message-Id: <20200122092813.374663816@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200122092803.587683021@linuxfoundation.org> References: <20200122092803.587683021@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 @@ -936,12 +936,18 @@ 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;