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=-5.4 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 BCFE5C35247 for ; Mon, 3 Feb 2020 18:28:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 978F12086A for ; Mon, 3 Feb 2020 18:28:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729783AbgBCS2N (ORCPT ); Mon, 3 Feb 2020 13:28:13 -0500 Received: from mail-il1-f199.google.com ([209.85.166.199]:45032 "EHLO mail-il1-f199.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727479AbgBCS2M (ORCPT ); Mon, 3 Feb 2020 13:28:12 -0500 Received: by mail-il1-f199.google.com with SMTP id h87so12698862ild.11 for ; Mon, 03 Feb 2020 10:28:12 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:message-id:subject:from:to; bh=fNirEIjUZWmHl3fUAVYFWGTvsAYsyyMxP84IDuD55uU=; b=hPL+YSmDAjO2bKFezKKFnrdCIrV/iRV2Xbs1brq/h+D9bILQv2SIEkaf0c7xSOuho6 YDOqfqs850HPvNa0PgpLjqIWEznFNt6VMm2LFRLxbf82Qhm3cnfAiHB/z+QHHmeogc7/ 7K3hF9qvIyPVCe9OZ6bLAqLGqQNvcTJ/KVn8AB5CvC0n+Hyb7GvB6X42AxnCrm9nWUQG 5+K46nTGLcpRDOcUl129To4pHGG1pA015db6QxWQaDGytJwkGOHnxIKHQTYBiAkJe8Qr 1IgiBSF6alRUj0iBFfpVzzMxYfPQ20LR/+PogDW6+1c9IRjNturGlYvhebiuU4kT3FVp w0Iw== X-Gm-Message-State: APjAAAVlKn1mJte2cRFiEjYaVVj4roL3CkL9QKCqW82/awhIaaEJma5B q0VPR+Ud6yetmM9TUgMRdQdCDKRzb8rDtHpxcczgDgpTWlbP X-Google-Smtp-Source: APXvYqxAnqBewG1iFwpsyVzj92urVpUN607Q5R7WgBJZrs7tq87ZBAeAdxyr34hRFZHw5wcrwspswcSloprUWaKraiBImuLSxIpZ MIME-Version: 1.0 X-Received: by 2002:a02:c906:: with SMTP id t6mr20831421jao.75.1580754491979; Mon, 03 Feb 2020 10:28:11 -0800 (PST) Date: Mon, 03 Feb 2020 10:28:11 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000f8bfe8059db01519@google.com> Subject: possible deadlock in wg_noise_handshake_create_initiation From: syzbot To: Jason@zx2c4.com, davem@davemloft.net, jason@zx2c4.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com, wireguard@lists.zx2c4.com Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: ccaaaf6f Merge tag 'mpx-for-linus' of git://git.kernel.org.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16034a79e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=3373595e41752b95 dashboard link: https://syzkaller.appspot.com/bug?extid=d5bc560aaa1cedefffd5 compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=103868b5e00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16dd064ee00000 The bug was bisected to: commit e7096c131e5161fa3b8e52a650d7719d2857adfd Author: Jason A. Donenfeld Date: Sun Dec 8 23:27:34 2019 +0000 net: WireGuard secure network tunnel bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14440195e00000 final crash: https://syzkaller.appspot.com/x/report.txt?x=16440195e00000 console output: https://syzkaller.appspot.com/x/log.txt?x=12440195e00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+d5bc560aaa1cedefffd5@syzkaller.appspotmail.com Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") ====================================================== WARNING: possible circular locking dependency detected 5.5.0-syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:4/509 is trying to acquire lock: ffff888097a30e80 (&wg->static_identity.lock){++++}, at: wg_noise_handshake_create_initiation+0x6a/0x15c0 drivers/net/wireguard/noise.c:499 but task is already holding lock: ffffc90002157d78 ((work_completion)(&peer->transmit_handshake_work)){+.+.}, at: process_one_work+0x7a5/0x10f0 kernel/workqueue.c:2239 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 ((work_completion)(&peer->transmit_handshake_work)){+.+.}: lock_acquire+0x154/0x250 kernel/locking/lockdep.c:4484 process_one_work+0x7c8/0x10f0 kernel/workqueue.c:2240 worker_thread+0xbbc/0x1630 kernel/workqueue.c:2410 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 -> #1 ((wq_completion)wg-kex-wireguard0){+.+.}: lock_acquire+0x154/0x250 kernel/locking/lockdep.c:4484 flush_workqueue+0x10a/0x1820 kernel/workqueue.c:2775 peer_remove_after_dead+0x125/0x280 drivers/net/wireguard/peer.c:141 wg_peer_remove+0x211/0x270 drivers/net/wireguard/peer.c:176 wg_set_device+0xb6a/0x2010 drivers/net/wireguard/netlink.c:575 genl_family_rcv_msg_doit net/netlink/genetlink.c:672 [inline] genl_family_rcv_msg net/netlink/genetlink.c:717 [inline] genl_rcv_msg+0xf15/0x13e0 net/netlink/genetlink.c:734 netlink_rcv_skb+0x19e/0x3e0 net/netlink/af_netlink.c:2477 genl_rcv+0x28/0x40 net/netlink/genetlink.c:745 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x766/0x920 net/netlink/af_netlink.c:1328 netlink_sendmsg+0xa2b/0xd40 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x4f7/0x7f0 net/socket.c:2343 ___sys_sendmsg net/socket.c:2397 [inline] __sys_sendmsg+0x1ed/0x290 net/socket.c:2430 __do_sys_sendmsg net/socket.c:2439 [inline] __se_sys_sendmsg net/socket.c:2437 [inline] __x64_sys_sendmsg+0x7f/0x90 net/socket.c:2437 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&wg->static_identity.lock){++++}: check_prev_add kernel/locking/lockdep.c:2475 [inline] check_prevs_add kernel/locking/lockdep.c:2580 [inline] validate_chain+0x1507/0x7be0 kernel/locking/lockdep.c:2970 __lock_acquire+0xc5a/0x1bc0 kernel/locking/lockdep.c:3954 lock_acquire+0x154/0x250 kernel/locking/lockdep.c:4484 down_read+0x39/0x50 kernel/locking/rwsem.c:1495 wg_noise_handshake_create_initiation+0x6a/0x15c0 drivers/net/wireguard/noise.c:499 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline] wg_packet_handshake_send_worker+0xe5/0x1a0 drivers/net/wireguard/send.c:51 process_one_work+0x7f5/0x10f0 kernel/workqueue.c:2264 worker_thread+0xbbc/0x1630 kernel/workqueue.c:2410 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 other info that might help us debug this: Chain exists of: &wg->static_identity.lock --> (wq_completion)wg-kex-wireguard0 --> (work_completion)(&peer->transmit_handshake_work) Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((work_completion)(&peer->transmit_handshake_work)); lock((wq_completion)wg-kex-wireguard0); lock((work_completion)(&peer->transmit_handshake_work)); lock(&wg->static_identity.lock); *** DEADLOCK *** 2 locks held by kworker/u4:4/509: #0: ffff88809ec44128 ((wq_completion)wg-kex-wireguard0){+.+.}, at: spin_unlock_irq include/linux/spinlock.h:388 [inline] #0: ffff88809ec44128 ((wq_completion)wg-kex-wireguard0){+.+.}, at: process_one_work+0x763/0x10f0 kernel/workqueue.c:2237 #1: ffffc90002157d78 ((work_completion)(&peer->transmit_handshake_work)){+.+.}, at: process_one_work+0x7a5/0x10f0 kernel/workqueue.c:2239 stack backtrace: CPU: 1 PID: 509 Comm: kworker/u4:4 Not tainted 5.5.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: wg-kex-wireguard0 wg_packet_handshake_send_worker Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fb/0x318 lib/dump_stack.c:118 print_circular_bug+0xc3f/0xe70 kernel/locking/lockdep.c:1684 check_noncircular+0x206/0x3a0 kernel/locking/lockdep.c:1808 check_prev_add kernel/locking/lockdep.c:2475 [inline] check_prevs_add kernel/locking/lockdep.c:2580 [inline] validate_chain+0x1507/0x7be0 kernel/locking/lockdep.c:2970 __lock_acquire+0xc5a/0x1bc0 kernel/locking/lockdep.c:3954 lock_acquire+0x154/0x250 kernel/locking/lockdep.c:4484 down_read+0x39/0x50 kernel/locking/rwsem.c:1495 wg_noise_handshake_create_initiation+0x6a/0x15c0 drivers/net/wireguard/noise.c:499 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline] wg_packet_handshake_send_worker+0xe5/0x1a0 drivers/net/wireguard/send.c:51 process_one_work+0x7f5/0x10f0 kernel/workqueue.c:2264 worker_thread+0xbbc/0x1630 kernel/workqueue.c:2410 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches