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=-14.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNWANTED_LANGUAGE_BODY,URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham 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 BE46EC433DF for ; Thu, 21 May 2020 18:30:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8C6CC207D3 for ; Thu, 21 May 2020 18:30:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="SNWiUqAA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729231AbgEUSaE (ORCPT ); Thu, 21 May 2020 14:30:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728240AbgEUSaE (ORCPT ); Thu, 21 May 2020 14:30:04 -0400 Received: from mail-qt1-x849.google.com (mail-qt1-x849.google.com [IPv6:2607:f8b0:4864:20::849]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 16D28C061A0E for ; Thu, 21 May 2020 11:30:03 -0700 (PDT) Received: by mail-qt1-x849.google.com with SMTP id m2so332054qtd.7 for ; Thu, 21 May 2020 11:30:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=XLS24cejbtc6Htky1a093lmIhjzBrNYI8TJ1SeDPjXw=; b=SNWiUqAAzgW/pxeTIJLY47L6u7nQZUvA68VJY1lqNmW+Qy4zqREM7jxmDPA9oeUVBy QBIsLOISWJi0vuI/I68/N/0hVo2C0kX0iQ+0BZCVN0lm+Y0NLA7ojct/g6sSNlvhA80n RoLwYB6/t7k21lP+IThvnkvMb9N3FkuKCesWf7WdOBWSMhQPsc2t/XICbH8YBpbAeGPb A/TIRWv51Ve7JOLIDRcCiOvMD9PIYjcA2+avNKoDez6ZPMSI36CFoJvr6HigZzbc7C4+ IjL4IAEIRORCfT3rt/b8IYlBxsZZxWn8YyYszh7QRXDHSstip4VQfqI0nfHgJbUDROha dfSA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=XLS24cejbtc6Htky1a093lmIhjzBrNYI8TJ1SeDPjXw=; b=YmINXHU46hK8PjUgwSREvcc5tM1TDMsI7TAfuVneeg3QuMTIImliX/rhDF74NPkgNg E6UlYAbA4Ik7VHtS7fvmPiGz9srE1cr/w43IzlD8sLrkCWzUeyvrSLgij9oL6CTANfas WoyN/jo8zCayjz8HkR4rqgE/tbNOO+LgKNK5JNSm0ZZ/9Zbi8GqcYvO6heU7hkQnH0nO NHXLKmW7Qs0pZDT0UgwBd9VwEPb22TOIEe/+wY1scJWXszeY6RHmnvOdrjDK58UvY4IJ XZtLCtCoLkwdjMmzdh15mLRLi97YmR1cuQzfUPAsW60yJYIT1Lvt8Hx6dqWJuz+7Yoh0 02xg== X-Gm-Message-State: AOAM532qHV5zTYnUkiIHiCOAQBCwd6b+v0o8DsRp2FTVjNAONqwbA8dp KvzS7osTBDmLvA0AZn4CYOKjlvLOBC+SFw== X-Google-Smtp-Source: ABdhPJy5c/g1BgNN/fpRuUMtbgZTuNiY/q8rfPsY4AujeOo3OucijGeVGmRur8rpo+6aQUPk572roFjC1Mvfjg== X-Received: by 2002:a05:6214:b0c:: with SMTP id u12mr47490qvj.242.1590085802178; Thu, 21 May 2020 11:30:02 -0700 (PDT) Date: Thu, 21 May 2020 11:29:58 -0700 Message-Id: <20200521182958.163436-1-edumazet@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.27.0.rc0.183.gde8f92d652-goog Subject: [PATCH net] tipc: block BH before using dst_cache From: Eric Dumazet To: "David S . Miller" Cc: netdev , Eric Dumazet , Eric Dumazet , Xin Long , Jon Maloy , syzbot Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org dst_cache_get() documents it must be used with BH disabled. sysbot reported : BUG: using smp_processor_id() in preemptible [00000000] code: /21697 caller is dst_cache_get+0x3a/0xb0 net/core/dst_cache.c:68 CPU: 0 PID: 21697 Comm: Not tainted 5.7.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 check_preemption_disabled lib/smp_processor_id.c:47 [inline] debug_smp_processor_id.cold+0x88/0x9b lib/smp_processor_id.c:57 dst_cache_get+0x3a/0xb0 net/core/dst_cache.c:68 tipc_udp_xmit.isra.0+0xb9/0xad0 net/tipc/udp_media.c:164 tipc_udp_send_msg+0x3e6/0x490 net/tipc/udp_media.c:244 tipc_bearer_xmit_skb+0x1de/0x3f0 net/tipc/bearer.c:526 tipc_enable_bearer+0xb2f/0xd60 net/tipc/bearer.c:331 __tipc_nl_bearer_enable+0x2bf/0x390 net/tipc/bearer.c:995 tipc_nl_bearer_enable+0x1e/0x30 net/tipc/bearer.c:1003 genl_family_rcv_msg_doit net/netlink/genetlink.c:673 [inline] genl_family_rcv_msg net/netlink/genetlink.c:718 [inline] genl_rcv_msg+0x627/0xdf0 net/netlink/genetlink.c:735 netlink_rcv_skb+0x15a/0x410 net/netlink/af_netlink.c:2469 genl_rcv+0x24/0x40 net/netlink/genetlink.c:746 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6bf/0x7e0 net/socket.c:2362 ___sys_sendmsg+0x100/0x170 net/socket.c:2416 __sys_sendmsg+0xec/0x1b0 net/socket.c:2449 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca29 Fixes: e9c1a793210f ("tipc: add dst_cache support for udp media") Cc: Xin Long Cc: Jon Maloy Signed-off-by: Eric Dumazet Reported-by: syzbot --- net/tipc/udp_media.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c index d6620ad535461a4d04ed5ba90569ce8b7df9f994..28a283f26a8dff24d613e6ed57e5e69d894dae66 100644 --- a/net/tipc/udp_media.c +++ b/net/tipc/udp_media.c @@ -161,9 +161,11 @@ static int tipc_udp_xmit(struct net *net, struct sk_buff *skb, struct udp_bearer *ub, struct udp_media_addr *src, struct udp_media_addr *dst, struct dst_cache *cache) { - struct dst_entry *ndst = dst_cache_get(cache); + struct dst_entry *ndst; int ttl, err = 0; + local_bh_disable(); + ndst = dst_cache_get(cache); if (dst->proto == htons(ETH_P_IP)) { struct rtable *rt = (struct rtable *)ndst; @@ -210,9 +212,11 @@ static int tipc_udp_xmit(struct net *net, struct sk_buff *skb, src->port, dst->port, false); #endif } + local_bh_enable(); return err; tx_error: + local_bh_enable(); kfree_skb(skb); return err; } -- 2.27.0.rc0.183.gde8f92d652-goog