From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754620AbdCBJmK (ORCPT ); Thu, 2 Mar 2017 04:42:10 -0500 Received: from mail-ua0-f171.google.com ([209.85.217.171]:33610 "EHLO mail-ua0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750771AbdCBJlf (ORCPT ); Thu, 2 Mar 2017 04:41:35 -0500 MIME-Version: 1.0 In-Reply-To: References:

From: Dmitry Vyukov Date: Thu, 2 Mar 2017 10:40:23 +0100 Message-ID: Subject: Re: net/ipv4: deadlock in ip_ra_control To: Cong Wang Cc: David Miller , Alexey Kuznetsov , James Morris , Hideaki YOSHIFUJI , Patrick McHardy , Eric Dumazet , netdev , LKML , syzkaller Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 1, 2017 at 6:18 PM, Cong Wang wrote: > On Wed, Mar 1, 2017 at 2:44 AM, Dmitry Vyukov wrote: >> Hello, >> >> I've got the following deadlock report while running syzkaller fuzzer >> on linux-next/51788aebe7cae79cb334ad50641347465fc188fd: >> >> ====================================================== >> [ INFO: possible circular locking dependency detected ] >> 4.10.0-next-20170301+ #1 Not tainted >> ------------------------------------------------------- >> syz-executor1/3394 is trying to acquire lock: >> (sk_lock-AF_INET){+.+.+.}, at: [] lock_sock >> include/net/sock.h:1460 [inline] >> (sk_lock-AF_INET){+.+.+.}, at: [] >> do_ip_setsockopt.isra.12+0x21c/0x3540 net/ipv4/ip_sockglue.c:652 >> >> but task is already holding lock: >> (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 >> net/core/rtnetlink.c:70 >> >> which lock already depends on the new lock. >> >> >> the existing dependency chain (in reverse order) is: >> >> -> #1 (rtnl_mutex){+.+.+.}: >> validate_chain kernel/locking/lockdep.c:2265 [inline] >> __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3338 >> lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3753 >> __mutex_lock_common kernel/locking/mutex.c:754 [inline] >> __mutex_lock+0x172/0x1730 kernel/locking/mutex.c:891 >> mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:906 >> rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70 >> mrtsock_destruct+0x86/0x2c0 net/ipv4/ipmr.c:1281 >> ip_ra_control+0x459/0x600 net/ipv4/ip_sockglue.c:372 >> do_ip_setsockopt.isra.12+0x1064/0x3540 net/ipv4/ip_sockglue.c:1161 >> ip_setsockopt+0x3a/0xb0 net/ipv4/ip_sockglue.c:1264 >> raw_setsockopt+0xb7/0xd0 net/ipv4/raw.c:839 >> sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2725 >> SYSC_setsockopt net/socket.c:1786 [inline] >> SyS_setsockopt+0x25c/0x390 net/socket.c:1765 >> entry_SYSCALL_64_fastpath+0x1f/0xc2 >> >> -> #0 (sk_lock-AF_INET){+.+.+.}: >> check_prev_add kernel/locking/lockdep.c:1828 [inline] >> check_prevs_add+0xa8f/0x19f0 kernel/locking/lockdep.c:1938 >> validate_chain kernel/locking/lockdep.c:2265 [inline] >> __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3338 >> lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3753 >> lock_sock_nested+0xcb/0x120 net/core/sock.c:2530 >> lock_sock include/net/sock.h:1460 [inline] >> do_ip_setsockopt.isra.12+0x21c/0x3540 net/ipv4/ip_sockglue.c:652 >> ip_setsockopt+0x3a/0xb0 net/ipv4/ip_sockglue.c:1264 >> tcp_setsockopt+0x82/0xd0 net/ipv4/tcp.c:2721 >> sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2725 >> SYSC_setsockopt net/socket.c:1786 [inline] >> SyS_setsockopt+0x25c/0x390 net/socket.c:1765 >> entry_SYSCALL_64_fastpath+0x1f/0xc2 >> > > Please try the attached patch (compile only). Pushed the patch to the bots. Thanks