From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753436AbdDLMFw (ORCPT ); Wed, 12 Apr 2017 08:05:52 -0400 Received: from mail-pf0-f172.google.com ([209.85.192.172]:33295 "EHLO mail-pf0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753278AbdDLMFt (ORCPT ); Wed, 12 Apr 2017 08:05:49 -0400 MIME-Version: 1.0 In-Reply-To: References:

From: Andrey Konovalov Date: Wed, 12 Apr 2017 14:05:47 +0200 Message-ID: Subject: Re: net/ipv4: deadlock in ip_ra_control To: Cong Wang Cc: Dmitry Vyukov , David Miller , Alexey Kuznetsov , James Morris , Hideaki YOSHIFUJI , Patrick McHardy , Eric Dumazet , netdev , LKML , syzkaller Content-Type: multipart/mixed; boundary=f403045d2660670038054cf7079a Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --f403045d2660670038054cf7079a Content-Type: text/plain; charset=UTF-8 On Mon, Mar 6, 2017 at 3:04 AM, Cong Wang wrote: > On Fri, Mar 3, 2017 at 10:43 AM, Dmitry Vyukov wrote: >> On Thu, Mar 2, 2017 at 10:40 AM, Dmitry Vyukov wrote: >>> 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 >> >> >> This patch triggers: > > Ah, update the patch to fix this. Hi Cong, I now have a reproducer for this bug (attached) and your patch fixes it. Could you send it? Thanks! > > -- > You received this message because you are subscribed to the Google Groups "syzkaller" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller+unsubscribe@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. --f403045d2660670038054cf7079a Content-Type: text/x-csrc; charset=US-ASCII; name="ipv4-ra-control-deadlock-poc.c" Content-Disposition: attachment; filename="ipv4-ra-control-deadlock-poc.c" Content-Transfer-Encoding: base64 X-Attachment-Id: f_j1exj1281 Ly8gYXV0b2dlbmVyYXRlZCBieSBzeXprYWxsZXIgKGh0dHA6Ly9naXRodWIuY29tL2dvb2dsZS9z eXprYWxsZXIpCgojaWZuZGVmIF9fTlJfbW1hcAojZGVmaW5lIF9fTlJfbW1hcCA5CiNlbmRpZgoj aWZuZGVmIF9fTlJfc29ja2V0CiNkZWZpbmUgX19OUl9zb2NrZXQgNDEKI2VuZGlmCiNpZm5kZWYg X19OUl9zZXRzb2Nrb3B0CiNkZWZpbmUgX19OUl9zZXRzb2Nrb3B0IDU0CiNlbmRpZgoKI2RlZmlu ZSBfR05VX1NPVVJDRQoKI2luY2x1ZGUgPHN5cy9pb2N0bC5oPgojaW5jbHVkZSA8c3lzL21tYW4u 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