From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ganesha.gnumonks.org (ganesha.gnumonks.org [213.95.27.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D5F631E3DF7; Wed, 30 Oct 2024 11:53:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.95.27.120 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730289209; cv=none; b=CPl2dRwJlwp59sJEoJeYOaSOwBxLkiXpuSbvA6sA18e7tyiehUrhk5AcD+EfxDXB9FeTwiWavrZC807gn1bDn5n+OjSqefSwDP2aWt3eayCStOnZEDFkwYW0gY/nXAiYGTxTCe4k0g++Qx17heO3rKs7TObo6xMNUDOi1bWS8Nw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730289209; c=relaxed/simple; bh=EyfUkNK1Hymwcs4wedWp2TTgq/yABRnCSExQ3A12iAE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HPaqzuFTAH0f3Ns/Tk7QNegdAGw/4Xuu4Dh3HW4S0JsS76Usq9MhCSwVb6D+RUaNulNuk3WykoHamCfEgjBKR+b8pM+u+7IpW0yyCb8slpOtgc/J6PequWHK8cdTtqXIaMgPh6tXI9uDmM9RWBNRE5B9wHRqWz/4rOo+FbMwilE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org; spf=pass smtp.mailfrom=gnumonks.org; arc=none smtp.client-ip=213.95.27.120 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gnumonks.org Received: from [78.30.37.63] (port=34058 helo=gnumonks.org) by ganesha.gnumonks.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1t67GI-00B8aE-67; Wed, 30 Oct 2024 12:53:21 +0100 Date: Wed, 30 Oct 2024 12:53:17 +0100 From: Pablo Neira Ayuso To: Dong Chenchen Cc: kadlec@netfilter.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, fw@strlen.de, kuniyu@amazon.com, netfilter-devel@vger.kernel.org, netdev@vger.kernel.org, yuehaibing@huawei.com Subject: Re: [PATCH net v2] net: netfilter: Fix use-after-free in get_info() Message-ID: References: <20241024014701.2086286-1-dongchenchen2@huawei.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20241024014701.2086286-1-dongchenchen2@huawei.com> X-Spam-Score: -1.8 (-) On Thu, Oct 24, 2024 at 09:47:01AM +0800, Dong Chenchen wrote: > ip6table_nat module unload has refcnt warning for UAF. call trace is: > > WARNING: CPU: 1 PID: 379 at kernel/module/main.c:853 module_put+0x6f/0x80 > Modules linked in: ip6table_nat(-) > CPU: 1 UID: 0 PID: 379 Comm: ip6tables Not tainted 6.12.0-rc4-00047-gc2ee9f594da8-dirty #205 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), > BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 > RIP: 0010:module_put+0x6f/0x80 > Call Trace: > > get_info+0x128/0x180 > do_ip6t_get_ctl+0x6a/0x430 > nf_getsockopt+0x46/0x80 > ipv6_getsockopt+0xb9/0x100 > rawv6_getsockopt+0x42/0x190 > do_sock_getsockopt+0xaa/0x180 > __sys_getsockopt+0x70/0xc0 > __x64_sys_getsockopt+0x20/0x30 > do_syscall_64+0xa2/0x1a0 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > Concurrent execution of module unload and get_info() trigered the warning. > The root cause is as follows: > > cpu0 cpu1 > module_exit > //mod->state = MODULE_STATE_GOING > ip6table_nat_exit > xt_unregister_template > kfree(t) > //removed from templ_list > getinfo() > t = xt_find_table_lock > list_for_each_entry(tmpl, &xt_templates[af]...) > if (strcmp(tmpl->name, name)) > continue; //table not found > try_module_get > list_for_each_entry(t, &xt_net->tables[af]...) > return t; //not get refcnt > module_put(t->me) //uaf > unregister_pernet_subsys > //remove table from xt_net list > > While xt_table module was going away and has been removed from > xt_templates list, we couldnt get refcnt of xt_table->me. Check > module in xt_net->tables list re-traversal to fix it. Applied, thanks