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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 9934CC12002 for ; Mon, 19 Jul 2021 15:01:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 862476024A for ; Mon, 19 Jul 2021 15:01:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242602AbhGSOVN (ORCPT ); Mon, 19 Jul 2021 10:21:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:56506 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242382AbhGSOTu (ORCPT ); Mon, 19 Jul 2021 10:19:50 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A009B61165; Mon, 19 Jul 2021 15:00:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626706829; bh=Fi1WOGB/gHgrOPil0YCRQlkbeL9NDzzccaMwb4AsXMc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pydUVFhdDgWxVuDLpWPAcTQna98f0gZkevuT0fdbw83JA/iRzuKDR+o+WyWLzM6Xz KTSMFjDUViq0QeeHhoRQV3dbUOy7/h7CAL7yxlnnTw/fCeXq/PhTQtuwWYmfmelDSS xmwEz4jiZvHKz+LTdeJG3E0iNcZNLBLv7Nnmyem0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , syzbot , "David S. Miller" , Sasha Levin Subject: [PATCH 4.4 073/188] vxlan: add missing rcu_read_lock() in neigh_reduce() Date: Mon, 19 Jul 2021 16:50:57 +0200 Message-Id: <20210719144930.039980271@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144913.076563739@linuxfoundation.org> References: <20210719144913.076563739@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet [ Upstream commit 85e8b032d6ebb0f698a34dd22c2f13443d905888 ] syzbot complained in neigh_reduce(), because rcu_read_lock_bh() is treated differently than rcu_read_lock() WARNING: suspicious RCU usage 5.13.0-rc6-syzkaller #0 Not tainted ----------------------------- include/net/addrconf.h:313 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 3 locks held by kworker/0:0/5: #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline] #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2247 #1: ffffc90000ca7da8 ((work_completion)(&port->wq)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2251 #2: ffffffff8bf795c0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1da/0x3130 net/core/dev.c:4180 stack backtrace: CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.13.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events ipvlan_process_multicast Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 __in6_dev_get include/net/addrconf.h:313 [inline] __in6_dev_get include/net/addrconf.h:311 [inline] neigh_reduce drivers/net/vxlan.c:2167 [inline] vxlan_xmit+0x34d5/0x4c30 drivers/net/vxlan.c:2919 __netdev_start_xmit include/linux/netdevice.h:4944 [inline] netdev_start_xmit include/linux/netdevice.h:4958 [inline] xmit_one net/core/dev.c:3654 [inline] dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3670 __dev_queue_xmit+0x2133/0x3130 net/core/dev.c:4246 ipvlan_process_multicast+0xa99/0xd70 drivers/net/ipvlan/ipvlan_core.c:287 process_one_work+0x98d/0x1600 kernel/workqueue.c:2276 worker_thread+0x64c/0x1120 kernel/workqueue.c:2422 kthread+0x3b1/0x4a0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Fixes: f564f45c4518 ("vxlan: add ipv6 proxy support") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/vxlan.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 50ede6b8b874..4d44ec5b7cd7 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -1549,6 +1549,7 @@ static int neigh_reduce(struct net_device *dev, struct sk_buff *skb) struct neighbour *n; struct inet6_dev *in6_dev; + rcu_read_lock(); in6_dev = __in6_dev_get(dev); if (!in6_dev) goto out; @@ -1605,6 +1606,7 @@ static int neigh_reduce(struct net_device *dev, struct sk_buff *skb) } out: + rcu_read_unlock(); consume_skb(skb); return NETDEV_TX_OK; } -- 2.30.2