From patchwork Wed Oct 14 08:56:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leon Romanovsky X-Patchwork-Id: 1381927 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=kernel.org Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=default header.b=gCR6i0LS; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4CB5rM0SnFz9sVR for ; Wed, 14 Oct 2020 19:56:51 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726773AbgJNI4u (ORCPT ); Wed, 14 Oct 2020 04:56:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:33194 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725970AbgJNI4u (ORCPT ); Wed, 14 Oct 2020 04:56:50 -0400 Received: from localhost (unknown [213.57.247.131]) (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 1338720725; Wed, 14 Oct 2020 08:56:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602665808; bh=Qc8dZfRYkcKX4pYqtu+HcTnKeAqRo/t0fMc78b3K9OA=; h=From:To:Cc:Subject:Date:From; b=gCR6i0LSw1rw+mgssiWVqN8slUTRh6miyp/j5JwkD7dWzHZ6FT3PbiKVP5gO9H8DZ FoMyqQ8FM7ej/Rd/HTbVSWuXH5opDM6/resMerN0dJfJvvIWSyWa5Cctvp7HX3yTKH eXQxziX28K7Bqto616yUViJ2F86LQZs3mQH35gmk= From: Leon Romanovsky To: "David S . Miller" , Jakub Kicinski Cc: Leon Romanovsky , Cong Wang , Ido Schimmel , Jamal Hadi Salim , Jiri Pirko , netdev@vger.kernel.org, Vlad Buslov Subject: [PATCH net] net: sched: Fix suspicious RCU usage while accessing tcf_tunnel_info Date: Wed, 14 Oct 2020 11:56:42 +0300 Message-Id: <20201014085642.21167-1-leon@kernel.org> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Leon Romanovsky The access of tcf_tunnel_info() produces the following splat, so fix it by dereferencing the tcf_tunnel_key_params pointer with marker that internal tcfa_liock is held. ============================= WARNING: suspicious RCU usage 5.9.0+ #1 Not tainted ----------------------------- include/net/tc_act/tc_tunnel_key.h:59 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by tc/34839: #0: ffff88828572c2a0 (&p->tcfa_lock){+...}-{2:2}, at: tc_setup_flow_action+0xb3/0x48b5 stack backtrace: CPU: 1 PID: 34839 Comm: tc Not tainted 5.9.0+ #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0x9a/0xd0 tc_setup_flow_action+0x14cb/0x48b5 fl_hw_replace_filter+0x347/0x690 [cls_flower] fl_change+0x2bad/0x4875 [cls_flower] tc_new_tfilter+0xf6f/0x1ba0 rtnetlink_rcv_msg+0x5f2/0x870 netlink_rcv_skb+0x124/0x350 netlink_unicast+0x433/0x700 netlink_sendmsg+0x6f1/0xbd0 sock_sendmsg+0xb0/0xe0 ____sys_sendmsg+0x4fa/0x6d0 ___sys_sendmsg+0x12e/0x1b0 __sys_sendmsg+0xa4/0x120 do_syscall_64+0x2d/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f1f8cd4fe57 Code: 0c 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10 RSP: 002b:00007ffdc1e193b8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1f8cd4fe57 RDX: 0000000000000000 RSI: 00007ffdc1e19420 RDI: 0000000000000003 RBP: 000000005f85aafa R08: 0000000000000001 R09: 00007ffdc1e1936c R10: 000000000040522d R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 00007ffdc1e1d6f0 R15: 0000000000482420 Fixes: 3ebaf6da0716 ("net: sched: Do not assume RTNL is held in tunnel key action helpers") Fixes: 7a47281439ba ("net: sched: lock action when translating it to flow_action infra") Signed-off-by: Leon Romanovsky Acked-by: Cong Wang --- include/net/tc_act/tc_tunnel_key.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) -- 2.26.2 diff --git a/include/net/tc_act/tc_tunnel_key.h b/include/net/tc_act/tc_tunnel_key.h index e1057b255f69..879fe8cff581 100644 --- a/include/net/tc_act/tc_tunnel_key.h +++ b/include/net/tc_act/tc_tunnel_key.h @@ -56,7 +56,10 @@ static inline struct ip_tunnel_info *tcf_tunnel_info(const struct tc_action *a) { #ifdef CONFIG_NET_CLS_ACT struct tcf_tunnel_key *t = to_tunnel_key(a); - struct tcf_tunnel_key_params *params = rtnl_dereference(t->params); + struct tcf_tunnel_key_params *params; + + params = rcu_dereference_protected(t->params, + lockdep_is_held(&a->tcfa_lock)); return ¶ms->tcft_enc_metadata->u.tun_info; #else