From nobody Tue Dec 16 04:37:20 2025 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 8DB0AC6FA97 for ; Mon, 26 Sep 2022 11:59:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239440AbiIZL65 (ORCPT ); Mon, 26 Sep 2022 07:58:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52404 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238603AbiIZLxb (ORCPT ); Mon, 26 Sep 2022 07:53:31 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7AA5E1EECA; Mon, 26 Sep 2022 03:49:39 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 34E2660A52; Mon, 26 Sep 2022 10:49:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4334CC433C1; Mon, 26 Sep 2022 10:49:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1664189378; bh=IJyVcokS76eYcgjYU/QcDdw9VqFByW+ywwfO1tCMjz8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r5FIVtzQXO+ggMRI5fPN4b/JYmp9d7F2anv8icohc3JDLWE+sAnwp2llsKa5k/woN SwGEK+zlTIF8z/hwg8RMSmOPS67x/r21nA4Z5mUSBEzJLKPL0NdVBxEv8tkDUtxEXC m0sO65zflDf2JneYe+szXMFx1izcRtRv3TEG+GhQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot , Tetsuo Handa , Florian Westphal , Sasha Levin Subject: [PATCH 5.19 137/207] netfilter: nf_tables: fix nft_counters_enabled underflow at nf_tables_addchain() Date: Mon, 26 Sep 2022 12:12:06 +0200 Message-Id: <20220926100812.649459985@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220926100806.522017616@linuxfoundation.org> References: <20220926100806.522017616@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Tetsuo Handa [ Upstream commit 921ebde3c0d22c8cba74ce8eb3cc4626abff1ccd ] syzbot is reporting underflow of nft_counters_enabled counter at nf_tables_addchain() [1], for commit 43eb8949cfdffa76 ("netfilter: nf_tables: do not leave chain stats enabled on error") missed that nf_tables_chain_destroy() after nft_basechain_init() in the error path of nf_tables_addchain() decrements the counter because nft_basechain_init() makes nft_is_base_chain() return true by setting NFT_CHAIN_BASE flag. Increment the counter immediately after returning from nft_basechain_init(). Link: https://syzkaller.appspot.com/bug?extid=3Db5d82a651b71cd8a75ab [1] Reported-by: syzbot Signed-off-by: Tetsuo Handa Tested-by: syzbot Fixes: 43eb8949cfdffa76 ("netfilter: nf_tables: do not leave chain stats en= abled on error") Signed-off-by: Florian Westphal Signed-off-by: Sasha Levin --- net/netfilter/nf_tables_api.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 848cc81d6992..3aaf36df69d4 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -2197,7 +2197,6 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8= family, u8 genmask, struct netlink_ext_ack *extack) { const struct nlattr * const *nla =3D ctx->nla; - struct nft_stats __percpu *stats =3D NULL; struct nft_table *table =3D ctx->table; struct nft_base_chain *basechain; struct net *net =3D ctx->net; @@ -2212,6 +2211,7 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8= family, u8 genmask, return -EOVERFLOW; =20 if (nla[NFTA_CHAIN_HOOK]) { + struct nft_stats __percpu *stats =3D NULL; struct nft_chain_hook hook; =20 if (flags & NFT_CHAIN_BINDING) @@ -2245,6 +2245,8 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8= family, u8 genmask, kfree(basechain); return err; } + if (stats) + static_branch_inc(&nft_counters_enabled); } else { if (flags & NFT_CHAIN_BASE) return -EINVAL; @@ -2319,9 +2321,6 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8= family, u8 genmask, goto err_unregister_hook; } =20 - if (stats) - static_branch_inc(&nft_counters_enabled); - table->use++; =20 return 0; --=20 2.35.1