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=-0.4 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 B3BFFC7618B for ; Fri, 26 Jul 2019 09:38:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 938E6229F9 for ; Fri, 26 Jul 2019 09:38:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726417AbfGZJiV (ORCPT ); Fri, 26 Jul 2019 05:38:21 -0400 Received: from mail-io1-f69.google.com ([209.85.166.69]:52170 "EHLO mail-io1-f69.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726138AbfGZJiH (ORCPT ); Fri, 26 Jul 2019 05:38:07 -0400 Received: by mail-io1-f69.google.com with SMTP id c5so57709028iom.18 for ; Fri, 26 Jul 2019 02:38:07 -0700 (PDT) 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=39Iz35mRNdj8tP+TDSA6C43v5ggwJ6FzRe1kzAV801U=; b=O1d9yky6CPT9oLw96OBanCxOM+zDAQwNlVw5JS6FbfVJXdANsVhyLce9vt+gR4mKD4 3Tq8kfEhcFGM0zp44GU0wd7qZ6pLV8CyKl+bdyrUrCP0MUUQCYLm1bKoaLzawnY3szWQ w74uVlTH7mWVpAUT0wlM1XPRRCcTD538wzWw4ZLuG31bx3OqmCW5q/Z4hrd9Pf0LlmCU tktwrvLrhX655MlX/GzfdOK4V1snjhQfjnyfwtG46MtNWSt0HEeAm2ZUSaCJOAIK4MSK NK3i/r8PDty9gHYWUoWfUmYfDlNoPzqsGc642JtmivYUtOzE3tNcupbgG7cADAdJ5eHi oTSg== X-Gm-Message-State: APjAAAUMFlvAou/qY9oAi0KNW5XLlkoLkrItObTyMLjet2/SJ/Hx7btw 6OVGfyXZTfVa4CUMT0AkZKCjb3V/bqBySWVf23rK9AHG6gyZ X-Google-Smtp-Source: APXvYqzQJnx5eS2Vg9aK9+kDrfFLZyTj0vfiOhdx/mgX5Rjd5uWJ1AfEt+x3TtstMmR5dFEfceDNOjAwrN6Rxc/S7t6s5gGZIklH MIME-Version: 1.0 X-Received: by 2002:a5d:9b1a:: with SMTP id y26mr21679500ion.238.1564133887025; Fri, 26 Jul 2019 02:38:07 -0700 (PDT) Date: Fri, 26 Jul 2019 02:38:07 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000b7abcc058e924c12@google.com> Subject: possible deadlock in rxrpc_put_peer From: syzbot To: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: 6d21a41b Add linux-next specific files for 20190718 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=174e3af0600000 kernel config: https://syzkaller.appspot.com/x/.config?x=3430a151e1452331 dashboard link: https://syzkaller.appspot.com/bug?extid=72af434e4b3417318f84 compiler: gcc (GCC) 9.0.0 20181231 (experimental) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+72af434e4b3417318f84@syzkaller.appspotmail.com ============================================ WARNING: possible recursive locking detected 5.2.0-next-20190718 #41 Not tainted -------------------------------------------- kworker/0:3/21678 is trying to acquire lock: 00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at: spin_lock_bh /./include/linux/spinlock.h:343 [inline] 00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at: __rxrpc_put_peer /net/rxrpc/peer_object.c:415 [inline] 00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at: rxrpc_put_peer+0x2d3/0x6a0 /net/rxrpc/peer_object.c:435 but task is already holding lock: 00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at: spin_lock_bh /./include/linux/spinlock.h:343 [inline] 00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at: rxrpc_peer_keepalive_dispatch /net/rxrpc/peer_event.c:378 [inline] 00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at: rxrpc_peer_keepalive_worker+0x6b3/0xd02 /net/rxrpc/peer_event.c:430 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&rxnet->peer_hash_lock)->rlock); lock(&(&rxnet->peer_hash_lock)->rlock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by kworker/0:3/21678: #0: 000000007c4c2bc3 ((wq_completion)krxrpcd){+.+.}, at: __write_once_size /./include/linux/compiler.h:226 [inline] #0: 000000007c4c2bc3 ((wq_completion)krxrpcd){+.+.}, at: arch_atomic64_set /./arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000007c4c2bc3 ((wq_completion)krxrpcd){+.+.}, at: atomic64_set /./include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000007c4c2bc3 ((wq_completion)krxrpcd){+.+.}, at: atomic_long_set /./include/asm-generic/atomic-long.h:40 [inline] #0: 000000007c4c2bc3 ((wq_completion)krxrpcd){+.+.}, at: set_work_data /kernel/workqueue.c:620 [inline] #0: 000000007c4c2bc3 ((wq_completion)krxrpcd){+.+.}, at: set_work_pool_and_clear_pending /kernel/workqueue.c:647 [inline] #0: 000000007c4c2bc3 ((wq_completion)krxrpcd){+.+.}, at: process_one_work+0x88b/0x1740 /kernel/workqueue.c:2240 #1: 000000006782bc7f ((work_completion)(&rxnet->peer_keepalive_work)){+.+.}, at: process_one_work+0x8c1/0x1740 /kernel/workqueue.c:2244 #2: 00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at: spin_lock_bh /./include/linux/spinlock.h:343 [inline] #2: 00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at: rxrpc_peer_keepalive_dispatch /net/rxrpc/peer_event.c:378 [inline] #2: 00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at: rxrpc_peer_keepalive_worker+0x6b3/0xd02 /net/rxrpc/peer_event.c:430 stack backtrace: CPU: 0 PID: 21678 Comm: kworker/0:3 Not tainted 5.2.0-next-20190718 #41 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: krxrpcd rxrpc_peer_keepalive_worker Call Trace: __dump_stack /lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 /lib/dump_stack.c:113 print_deadlock_bug /kernel/locking/lockdep.c:2301 [inline] check_deadlock /kernel/locking/lockdep.c:2342 [inline] validate_chain /kernel/locking/lockdep.c:2881 [inline] __lock_acquire.cold+0x194/0x398 /kernel/locking/lockdep.c:3880 lock_acquire+0x190/0x410 /kernel/locking/lockdep.c:4413 __raw_spin_lock_bh /./include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x33/0x50 /kernel/locking/spinlock.c:175 spin_lock_bh /./include/linux/spinlock.h:343 [inline] __rxrpc_put_peer /net/rxrpc/peer_object.c:415 [inline] rxrpc_put_peer+0x2d3/0x6a0 /net/rxrpc/peer_object.c:435 rxrpc_peer_keepalive_dispatch /net/rxrpc/peer_event.c:381 [inline] rxrpc_peer_keepalive_worker+0x7a6/0xd02 /net/rxrpc/peer_event.c:430 process_one_work+0x9af/0x1740 /kernel/workqueue.c:2269 worker_thread+0x98/0xe40 /kernel/workqueue.c:2415 kthread+0x361/0x430 /kernel/kthread.c:255 ret_from_fork+0x24/0x30 /arch/x86/entry/entry_64.S:352 --- This bug is generated by a bot. 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