From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794590406; b=4FwVqxc53Vbd/1XiAdVJmFWsCsf5Wg35doxOqyWQocaXFWaB9394SmwiQ2y6PJEiqb+8 NN8b0XL+HcwwVOSPa0h8ocYV5aDt7AlOFAFiKnKR13d8ByMzIC5hfwLKzLcmd7RtMI6Fi YOJMG9sX1J2xQKnUT/bcswibu133tEMweWKIoz20RLxoafzW9sQDvOYIfr7SL+vw7eTta c0USdH+96d2JNUF6E+YU/HjbrLdtxspN8m4TKj3cua/resLKiiLxZQxeLxfE/p1SkZQK4 U5QtPd8qqs20Dm5oehz9ouiZ0PTMnxXFosJVT9wsdxhvp7N3mg3GeOtb8E7bJeUZPFw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794590406; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=pLe6c2LhWdg08aU3SLTnHU4DwBkAqigblBo0XXQ9BX0=; b=KApGcv9qsVC0ER7M0aBItfkgSix4Z6zeKOntRu6dqsRQwDV1J46pD89xsxYU2ZkDQz8v RTdSn0kFZt0WogU0v/L4DXLiqUfR+hZgrWE/vH51fqlH058bupRuPuDKqw/jzWEi0TRIC sNQ+1GmgOyyEOssh53DoKGGmQzlnMhROmCKrWPo5LpOXoE5teJyEDNonH0nt3YBdrr/2y KYNOvoDq9yMqBpoLvtfSlYv1wrlVax8z8k72pPLJyWzXhAx/YJzjQiMmM2G4HpyR2YMrF 9EXjfct49Ae6BhP6OJ2rUJ4b+6gGwQlbqaeYLvbnl3RoUkIM5fJbkUuFlWhSjyal1dg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=gYBGfrXt; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5FB58606B462; Fri, 13 Nov 2026 17:20:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=gYBGfrXt Received: by smtp.kernel.org (Postfix) with ESMTPSA id E21151F000C6; Fri, 13 Nov 2026 17:19:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794590406; bh=pLe6c2LhWdg08aU3SLTnHU4DwBkAqigblBo0XXQ9BX0=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=gYBGfrXt2Ffp3CtT9lRu9Q4s81KSZzKqz9Lfo+PVwqO3aGrdqToyoAZeMLYx+juiA KtFrHhDOvqWjuv5gegWK1CFAegTV4RmiedbGywGgJfdkE+pu8ys3/EGxWW02qZWFpy HofAGIVx8fwFyNPwBLWF72gY4Vqk3SMEO1Pwq9eBSjoYvk8yZSUJKySbESzKGszr4o iCc/ryB4FO6VPjWC8EgEQeu7AWL8RDX4I+OW3weY7cfxZZCq9A8Z3l+mJkz84ZgeQI 44bi4zPENd8IWPJH6wv4vXH4sIppBMhelgZjQY5z49TqHo3iXU4rYX3ca2x1J5HiGC ZVsqI99IAXQAA== Date: Fri, 13 Nov 2026 17:19:57 +0000 From: Simon Horman To: Jiayuan Chen Cc: netdev@vger.kernel.org, David Ahern , Ido Schimmel , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Pablo Neira Ayuso , Florian Westphal , Phil Sutter , Nikolay Aleksandrov , Paul Moore , Matthieu Baerts , Mat Martineau , Geliang Tang , Julian Anastasov , Allison Henderson , Marcelo Ricardo Leitner , Xin Long , "D. Wythe" , Dust Li , Sidraya Jayagond , Mahanta Jambigi , Tony Lu , Wen Gu , linux-kernel@vger.kernel.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, bridge@lists.linux.dev, linux-security-module@vger.kernel.org, mptcp@lists.linux.dev, lvs-devel@vger.kernel.org, linux-rdma@vger.kernel.org, rds-devel@oss.oracle.com, linux-sctp@vger.kernel.org, linux-s390@vger.kernel.org Subject: Re: [PATCH net-next 13/14] netfilter: conntrack: annotate data-races around timeout and tcp sysctls Message-ID: <20261113171957.GV18859@horms.kernel.org> References: <20261109025425.328445-1-jiayuan.chen@linux.dev> <20261109025425.328445-14-jiayuan.chen@linux.dev> X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261109025425.328445-14-jiayuan.chen@linux.dev> On Mon, Nov 09, 2026 at 10:52:12AM +0800, Jiayuan Chen wrote: > The nf_conntrack_*_timeout* knobs, nf_flowtable_tcp_timeout, > nf_flowtable_udp_timeout and nf_conntrack_tcp_{loose,be_liberal, > max_retrans,ignore_invalid_rst} are read in the packet path without any > lock while their sysctl handlers update them with WRITE_ONCE(). Add > READ_ONCE() to the readers. > > KCSAN reports it when nf_conntrack_udp_timeout is changed while UDP > traffic goes through conntrack: > > BUG: KCSAN: data-race in nf_conntrack_udp_packet / proc_int_u2k_conv_uop > > write (marked) to 0xffffffffb0829bc4 of 4 bytes by task 436 on cpu 0: > proc_int_u2k_conv_uop+0x92/0xa0 > sysctl_u2k_int_conv_hz+0x21/0x30 > proc_int_conv+0xdf/0x130 > do_proc_int_conv_jiffies+0x1b/0x30 > proc_vec_conv+0x21/0x40 > proc_vec+0x21e/0x6f0 > proc_dointvec_conv+0x21/0x40 > proc_dointvec_jiffies+0x15/0x30 > proc_sys_call_handler+0x282/0x3a0 > proc_sys_write+0x13/0x20 > ... > > read to 0xffffffffb0829bc4 of 4 bytes by task 439 on cpu 3: > nf_conntrack_udp_packet+0x27b/0x550 > nf_conntrack_in+0x767/0xb20 > ipv4_conntrack_local+0xb0/0x120 > nf_hook_slow+0x7e/0x180 > nf_hook+0x1fa/0x4e0 > __ip_local_out+0x1ac/0x3f0 > ip_send_skb+0x31/0x120 > udp_send_skb+0x4bf/0x640 > udp_sendmsg+0xdec/0x18a0 > ... > > value changed: 0x00001d4c -> 0x00001e46 > > Signed-off-by: Jiayuan Chen Reviewed-by: Simon Horman