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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 C0E80C43603 for ; Thu, 5 Dec 2019 04:59:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 821BE2077B for ; Thu, 5 Dec 2019 04:59:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="MO0bZWnn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728522AbfLEE7P (ORCPT ); Wed, 4 Dec 2019 23:59:15 -0500 Received: from mail-pg1-f196.google.com ([209.85.215.196]:45175 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728132AbfLEE7O (ORCPT ); Wed, 4 Dec 2019 23:59:14 -0500 Received: by mail-pg1-f196.google.com with SMTP id b9so594675pgk.12; Wed, 04 Dec 2019 20:59:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=CF8x3VrR2Pk+sxRcq7v1LTaWVHmEXKkfx7F0Ltpl8E4=; b=MO0bZWnnyP3YR8zCQUG8Gel4ZQQDRc5ytIhyrG03o5BN2THsCVajluPAlW5tG6mI1j AGvZA8oELyjfErjTpDTaBA2f/cKHaNX4E7B1YIw71IdcuDZ29NCU2sA3jOivsCJB9bSf lxWOyh66ETyWMtlZOmT5kblHMgjHaRc470ez0DVwhCgjvO/5V4rhOmudzN+6ffeFozu6 dANYA+OqCZL0vNPVvP6D6ArYnfah9yenOKvGKBhNnmo47Mvlsicm0ItYPbQcY41mZcDC Ji6FMbWM816UXXK2qHNzt+Wsr9TQebq6IxzLhiGd4WfG0wY2oLaoVACoUgpY8eW/PJ8F J3Jw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=CF8x3VrR2Pk+sxRcq7v1LTaWVHmEXKkfx7F0Ltpl8E4=; b=AXP41r7TOq3Zd0SVa+S5naXtfsnkOF6UXNj2xa+YnQ8ovJIvXE/nUFAmophj9TZk9b hXyi7V2e0FWlNUupwVeY3nWC92rRhfdhReW6oHauCpjUUqgMh2YaBW2z/m7uf9PZP9v3 FviQK4gAap4SnnIrlqMkOSFClW0fqHiIbIANBspqJOn+u/ThhvBUXEH4EdbTZmn6KZHr Yqq4I2wdYl1/Xfvk4mieUX4tm0O8a4fXUfRZfZDQjCfq5WaR2oh/TacAv3SidFN7ieb2 DQS5kBpxaQ+IwT/xvo7rCdmtpLyEB6Ish/ciIAEwhWIVCHxvtQAKlAer9j/0b9LZzITF u0Jg== X-Gm-Message-State: APjAAAUAUsVM0FWpo0h28qiofsDBASyluh1zHc5UiCDr18rJxKeQtUA1 mmCHJQ41tZx0F/Ijcyh+2Gw= X-Google-Smtp-Source: APXvYqwc7mawFYelljrN3i+IgimkjkUk0rbq+HGaOW9YhKJJgqqGWysfn1l/lttFhi22KHsJ4+8fvg== X-Received: by 2002:a65:4506:: with SMTP id n6mr7430520pgq.105.1575521953743; Wed, 04 Dec 2019 20:59:13 -0800 (PST) Received: from [192.168.86.235] (c-73-241-150-58.hsd1.ca.comcast.net. [73.241.150.58]) by smtp.gmail.com with ESMTPSA id y38sm9457497pgk.33.2019.12.04.20.59.12 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 04 Dec 2019 20:59:13 -0800 (PST) Subject: Re: BUG: sleeping function called from invalid context in lock_sock_nested To: syzbot , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk, Herbert Xu References: <0000000000003e5aa90598ed7415@google.com> From: Eric Dumazet Message-ID: Date: Wed, 4 Dec 2019 20:59:11 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <0000000000003e5aa90598ed7415@google.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 12/4/19 8:35 PM, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit:    63de3747 Merge tag 'tag-chrome-platform-for-v5.5' of git:/.. > git tree:       upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=1727d59ce00000 > kernel config:  https://syzkaller.appspot.com/x/.config?x=1d189d07c6717979 > dashboard link: https://syzkaller.appspot.com/bug?extid=c2f1558d49e25cc36e5e > compiler:       gcc (GCC) 9.0.0 20181231 (experimental) > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16fcf97ee00000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+c2f1558d49e25cc36e5e@syzkaller.appspotmail.com > > BUG: sleeping function called from invalid context at net/core/sock.c:2935 > in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 9008, name: udevd > 4 locks held by udevd/9008: >  #0: ffff888098598428 (sb_writers#5){.+.+}, at: sb_start_write include/linux/fs.h:1650 [inline] >  #0: ffff888098598428 (sb_writers#5){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:354 >  #1: ffff8880a02bb248 (&type->i_mutex_dir_key#4/1){+.+.}, at: inode_lock_nested include/linux/fs.h:826 [inline] >  #1: ffff8880a02bb248 (&type->i_mutex_dir_key#4/1){+.+.}, at: filename_create+0x17c/0x4f0 fs/namei.c:3630 >  #2: ffffffff89bb27a8 (tomoyo_ss){....}, at: tomoyo_path_perm+0x1cb/0x430 security/tomoyo/file.c:847 >  #3: ffffffff897a3fc0 (rcu_callback){....}, at: __rcu_reclaim kernel/rcu/rcu.h:210 [inline] >  #3: ffffffff897a3fc0 (rcu_callback){....}, at: rcu_do_batch kernel/rcu/tree.c:2183 [inline] >  #3: ffffffff897a3fc0 (rcu_callback){....}, at: rcu_core+0x5f8/0x1540 kernel/rcu/tree.c:2408 > Preemption disabled at: > [] __do_softirq+0xf3/0x98c kernel/softirq.c:269 > CPU: 1 PID: 9008 Comm: udevd Not tainted 5.4.0-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: >   >  __dump_stack lib/dump_stack.c:77 [inline] >  dump_stack+0x197/0x210 lib/dump_stack.c:118 >  ___might_sleep.cold+0x1fb/0x23e kernel/sched/core.c:6800 >  __might_sleep+0x95/0x190 kernel/sched/core.c:6753 >  lock_sock_nested+0x39/0x120 net/core/sock.c:2935 >  lock_sock include/net/sock.h:1526 [inline] >  af_alg_release_parent+0x1a6/0x290 crypto/af_alg.c:137 >  hash_sock_destruct+0x164/0x1c0 crypto/algif_hash.c:423 >  __sk_destruct+0x53/0x7f0 net/core/sock.c:1695 >  __rcu_reclaim kernel/rcu/rcu.h:222 [inline] >  rcu_do_batch kernel/rcu/tree.c:2183 [inline] >  rcu_core+0x570/0x1540 kernel/rcu/tree.c:2408 >  rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2417 >  __do_softirq+0x262/0x98c kernel/softirq.c:292 >  invoke_softirq kernel/softirq.c:373 [inline] >  irq_exit+0x19b/0x1e0 kernel/softirq.c:413 >  exiting_irq arch/x86/include/asm/apic.h:536 [inline] >  smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1137 >  apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 >   > RIP: 0010:__read_once_size include/linux/compiler.h:199 [inline] > RIP: 0010:check_kcov_mode kernel/kcov.c:70 [inline] > RIP: 0010:__sanitizer_cov_trace_pc+0x20/0x50 kernel/kcov.c:102 > Code: ff cc cc cc cc cc cc cc cc cc 55 48 89 e5 65 48 8b 04 25 c0 1e 02 00 65 8b 15 34 23 8d 7e 81 e2 00 01 1f 00 48 8b 75 08 75 2b <8b> 90 80 13 00 00 83 fa 02 75 20 48 8b 88 88 13 00 00 8b 80 84 13 > RSP: 0018:ffffc90001d67a58 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 > RAX: ffff88809ac86680 RBX: 0000000000000011 RCX: ffffffff835559d0 > RDX: 0000000000000000 RSI: ffffffff8355597e RDI: 0000000000000003 > RBP: ffffc90001d67a58 R08: ffff88809ac86680 R09: ffffed1014154557 > R10: ffffed1014154556 R11: ffff8880a0aa2ab7 R12: dffffc0000000000 > R13: ffff8880a0aa2ab0 R14: ffffc90001d67ba0 R15: 0000000000000011 >  tomoyo_check_acl+0x28e/0x3e0 security/tomoyo/domain.c:181 >  tomoyo_path_permission security/tomoyo/file.c:586 [inline] >  tomoyo_path_permission+0x1fb/0x360 security/tomoyo/file.c:573 >  tomoyo_path_perm+0x374/0x430 security/tomoyo/file.c:838 >  tomoyo_path_symlink+0xaa/0xf0 security/tomoyo/tomoyo.c:206 >  security_path_symlink+0x10a/0x170 security/security.c:1053 >  do_symlinkat+0x137/0x290 fs/namei.c:4148 >  __do_sys_symlink fs/namei.c:4169 [inline] >  __se_sys_symlink fs/namei.c:4167 [inline] >  __x64_sys_symlink+0x59/0x80 fs/namei.c:4167 >  do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 >  entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x7f68d8603517 > Code: 09 01 00 00 0f 05 48 3d 00 f0 ff ff 77 02 f3 c3 48 8b 15 14 39 2b 00 f7 d8 64 89 02 83 c8 ff c3 90 90 90 b8 58 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d f1 38 2b 00 31 d2 48 29 c2 64 > RSP: 002b:00007ffc322deae8 EFLAGS: 00000206 ORIG_RAX: 0000000000000058 > RAX: ffffffffffffffda RBX: 00000000025b6250 RCX: 00007f68d8603517 > RDX: 0000000000000002 RSI: 00007ffc322deb10 RDI: 00000000025cf730 > RBP: 00000000025b62d0 R08: 00007ffc322de6c0 R09: 00007f68d8657de0 > R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000032 > R13: 00000000025c7970 R14: 00000000025b6250 R15: 000000000000000b > > ================================ > WARNING: inconsistent lock state > 5.4.0-syzkaller #0 Tainted: G        W > -------------------------------- > inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. > udevd/9008 [HC0[0]:SC1[3]:HE1:SE0] takes: > ffff88809f5a9110 (sk_lock-AF_ALG){+.?.}, at: lock_sock include/net/sock.h:1526 [inline] > ffff88809f5a9110 (sk_lock-AF_ALG){+.?.}, at: af_alg_release_parent+0x1a6/0x290 crypto/af_alg.c:137 > {SOFTIRQ-ON-W} state was registered at: >   __trace_hardirqs_on_caller kernel/locking/lockdep.c:3389 [inline] >   lockdep_hardirqs_on+0x421/0x5e0 kernel/locking/lockdep.c:3434 >   trace_hardirqs_on+0x67/0x240 kernel/trace/trace_preemptirq.c:31 >   __local_bh_enable_ip+0x15a/0x270 kernel/softirq.c:194 >   local_bh_enable include/linux/bottom_half.h:32 [inline] >   lock_sock_nested+0xe2/0x120 net/core/sock.c:2945 >   lock_sock include/net/sock.h:1526 [inline] >   alg_bind+0x288/0x570 crypto/af_alg.c:187 >   __sys_bind+0x239/0x290 net/socket.c:1649 >   __do_sys_bind net/socket.c:1660 [inline] >   __se_sys_bind net/socket.c:1658 [inline] >   __x64_sys_bind+0x73/0xb0 net/socket.c:1658 >   do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 >   entry_SYSCALL_64_after_hwframe+0x49/0xbe > irq event stamp: 55316 > hardirqs last  enabled at (55316): [] trace_hardirqs_on_thunk+0x1a/0x1c arch/x86/entry/thunk_64.S:41 > hardirqs last disabled at (55315): [] trace_hardirqs_off_thunk+0x1a/0x1c arch/x86/entry/thunk_64.S:42 > softirqs last  enabled at (53682): [] memcpy include/linux/string.h:380 [inline] > softirqs last  enabled at (53682): [] fpu__copy+0x17e/0x8c0 arch/x86/kernel/fpu/core.c:195 > softirqs last disabled at (55075): [] invoke_softirq kernel/softirq.c:373 [inline] > softirqs last disabled at (55075): [] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 > > other info that might help us debug this: >  Possible unsafe locking scenario: > >        CPU0 >        ---- >   lock(sk_lock-AF_ALG); >   >     lock(sk_lock-AF_ALG); > >  *** DEADLOCK *** > > 4 locks held by udevd/9008: >  #0: ffff888098598428 (sb_writers#5){.+.+}, at: sb_start_write include/linux/fs.h:1650 [inline] >  #0: ffff888098598428 (sb_writers#5){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:354 >  #1: ffff8880a02bb248 (&type->i_mutex_dir_key#4/1){+.+.}, at: inode_lock_nested include/linux/fs.h:826 [inline] >  #1: ffff8880a02bb248 (&type->i_mutex_dir_key#4/1){+.+.}, at: filename_create+0x17c/0x4f0 fs/namei.c:3630 >  #2: ffffffff89bb27a8 (tomoyo_ss){....}, at: tomoyo_path_perm+0x1cb/0x430 security/tomoyo/file.c:847 >  #3: ffffffff897a3fc0 (rcu_callback){....}, at: __rcu_reclaim kernel/rcu/rcu.h:210 [inline] >  #3: ffffffff897a3fc0 (rcu_callback){....}, at: rcu_do_batch kernel/rcu/tree.c:2183 [inline] >  #3: ffffffff897a3fc0 (rcu_callback){....}, at: rcu_core+0x5f8/0x1540 kernel/rcu/tree.c:2408 > > stack backtrace: > CPU: 1 PID: 9008 Comm: udevd Tainted: G        W         5.4.0-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: >   >  __dump_stack lib/dump_stack.c:77 [inline] >  dump_stack+0x197/0x210 lib/dump_stack.c:118 >  print_usage_bug.cold+0x327/0x378 kernel/locking/lockdep.c:3101 >  valid_state kernel/locking/lockdep.c:3112 [inline] >  mark_lock_irq kernel/locking/lockdep.c:3309 [inline] >  mark_lock+0xbb4/0x1220 kernel/locking/lockdep.c:3666 >  mark_usage kernel/locking/lockdep.c:3566 [inline] >  __lock_acquire+0x1e8e/0x4a00 kernel/locking/lockdep.c:3909 >  lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485 >  lock_sock_nested+0xcb/0x120 net/core/sock.c:2944 >  lock_sock include/net/sock.h:1526 [inline] >  af_alg_release_parent+0x1a6/0x290 crypto/af_alg.c:137 >  hash_sock_destruct+0x164/0x1c0 crypto/algif_hash.c:423 >  __sk_destruct+0x53/0x7f0 net/core/sock.c:1695 >  __rcu_reclaim kernel/rcu/rcu.h:222 [inline] >  rcu_do_batch kernel/rcu/tree.c:2183 [inline] >  rcu_core+0x570/0x1540 kernel/rcu/tree.c:2408 >  rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2417 >  __do_softirq+0x262/0x98c kernel/softirq.c:292 >  invoke_softirq kernel/softirq.c:373 [inline] >  irq_exit+0x19b/0x1e0 kernel/softirq.c:413 >  exiting_irq arch/x86/include/asm/apic.h:536 [inline] >  smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1137 >  apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 >   > RIP: 0010:__read_once_size include/linux/compiler.h:199 [inline] > RIP: 0010:check_kcov_mode kernel/kcov.c:70 [inline] > RIP: 0010:__sanitizer_cov_trace_pc+0x20/0x50 kernel/kcov.c:102 > Code: ff cc cc cc cc cc cc cc cc cc 55 48 89 e5 65 48 8b 04 25 c0 1e 02 00 65 8b 15 34 23 8d 7e 81 e2 00 01 1f 00 48 8b 75 08 75 2b <8b> 90 80 13 00 00 83 fa 02 75 20 48 8b 88 88 13 00 00 8b 80 84 13 > RSP: 0018:ffffc90001d67a58 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 > RAX: ffff88809ac86680 RBX: 0000000000000011 RCX: ffffffff835559d0 > RDX: 0000000000000000 RSI: ffffffff8355597e RDI: 0000000000000003 > RBP: ffffc90001d67a58 R08: ffff88809ac86680 R09: ffffed1014154557 > R10: ffffed1014154556 R11: ffff8880a0aa2ab7 R12: dffffc0000000000 > R13: ffff8880a0aa2ab0 R14: ffffc90001d67ba0 R15: 0000000000000011 >  tomoyo_check_acl+0x28e/0x3e0 security/tomoyo/domain.c:181 >  tomoyo_path_permission security/tomoyo/file.c:586 [inline] >  tomoyo_path_permission+0x1fb/0x360 security/tomoyo/file.c:573 >  tomoyo_path_perm+0x374/0x430 security/tomoyo/file.c:838 >  tomoyo_path_symlink+0xaa/0xf0 security/tomoyo/tomoyo.c:206 >  security_path_symlink+0x10a/0x170 security/security.c:1053 >  do_symlinkat+0x137/0x290 fs/namei.c:4148 >  __do_sys_symlink fs/namei.c:4169 [inline] >  __se_sys_symlink fs/namei.c:4167 [inline] >  __x64_sys_symlink+0x59/0x80 fs/namei.c:4167 >  do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 >  entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x7f68d8603517 > Code: 09 01 00 00 0f 05 48 3d 00 f0 ff ff 77 02 f3 c3 48 8b 15 14 39 2b 00 f7 d8 64 89 02 83 c8 ff c3 90 90 90 b8 58 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d f1 38 2b 00 31 d2 48 29 c2 64 > RSP: 002b:00007ffc322deae8 EFLAGS: 00000206 ORIG_RAX: 0000000000000058 > RAX: ffffffffffffffda RBX: 00000000025b6250 RCX: 00007f68d8603517 > RDX: 0000000000000002 RSI: 00007ffc322deb10 RDI: 00000000025cf730 > RBP: 00000000025b62d0 R08: 00007ffc322de6c0 R09: 00007f68d8657de0 > R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000032 > R13: 00000000025c7970 R14: 00000000025b6250 R15: 000000000000000b > BUG: sleeping function called from invalid context at net/core/sock.c:2935 > in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 16, name: ksoftirqd/1 > INFO: lockdep is turned off. > Preemption disabled at: > [] __do_softirq+0xf3/0x98c kernel/softirq.c:269 > CPU: 1 PID: 16 Comm: ksoftirqd/1 Tainted: G        W         5.4.0-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: >  __dump_stack lib/dump_stack.c:77 [inline] >  dump_stack+0x197/0x210 lib/dump_stack.c:118 >  ___might_sleep.cold+0x1fb/0x23e kernel/sched/core.c:6800 >  __might_sleep+0x95/0x190 kernel/sched/core.c:6753 >  lock_sock_nested+0x39/0x120 net/core/sock.c:2935 >  lock_sock include/net/sock.h:1526 [inline] >  af_alg_release_parent+0x1a6/0x290 crypto/af_alg.c:137 >  hash_sock_destruct+0x164/0x1c0 crypto/algif_hash.c:423 >  __sk_destruct+0x53/0x7f0 net/core/sock.c:1695 >  __rcu_reclaim kernel/rcu/rcu.h:222 [inline] >  rcu_do_batch kernel/rcu/tree.c:2183 [inline] >  rcu_core+0x570/0x1540 kernel/rcu/tree.c:2408 >  rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2417 >  __do_softirq+0x262/0x98c kernel/softirq.c:292 >  run_ksoftirqd kernel/softirq.c:603 [inline] >  run_ksoftirqd+0x8e/0x110 kernel/softirq.c:595 >  smpboot_thread_fn+0x6a3/0xa40 kernel/smpboot.c:165 >  kthread+0x361/0x430 kernel/kthread.c:255 >  ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 > BUG: sleeping function called from invalid context at net/core/sock.c:2935 > in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 16, name: ksoftirqd/1 > INFO: lockdep is turned off. > Preemption disabled at: > [] __do_softirq+0xf3/0x98c kernel/softirq.c:269 > CPU: 1 PID: 16 Comm: ksoftirqd/1 Tainted: G        W         5.4.0-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: >  __dump_stack lib/dump_stack.c:77 [inline] >  dump_stack+0x197/0x210 lib/dump_stack.c:118 >  ___might_sleep.cold+0x1fb/0x23e kernel/sched/core.c:6800 >  __might_sleep+0x95/0x190 kernel/sched/core.c:6753 >  lock_sock_nested+0x39/0x120 net/core/sock.c:2935 >  lock_sock include/net/sock.h:1526 [inline] >  af_alg_release_parent+0x1a6/0x290 crypto/af_alg.c:137 >  hash_sock_destruct+0x164/0x1c0 crypto/algif_hash.c:423 >  __sk_destruct+0x53/0x7f0 net/core/sock.c:1695 >  __rcu_reclaim kernel/rcu/rcu.h:222 [inline] >  rcu_do_batch kernel/rcu/tree.c:2183 [inline] >  rcu_core+0x570/0x1540 kernel/rcu/tree.c:2408 >  rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2417 >  __do_softirq+0x262/0x98c kernel/softirq.c:292 >  run_ksoftirqd kernel/softirq.c:603 [inline] >  run_ksoftirqd+0x8e/0x110 kernel/softirq.c:595 >  smpboot_thread_fn+0x6a3/0xa40 kernel/smpboot.c:165 >  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. 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. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches crypto layer (hash_sock_destruct()) is called from rcu callback (this in BH context) but tries to grab a socket lock. A socket lock can schedule, which is illegal in BH context.