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=-8.7 required=3.0 tests=BAYES_00,FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 5049CC43467 for ; Thu, 8 Oct 2020 12:15:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F24B621D43 for ; Thu, 8 Oct 2020 12:15:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729698AbgJHMPY (ORCPT ); Thu, 8 Oct 2020 08:15:24 -0400 Received: from mail-io1-f69.google.com ([209.85.166.69]:32791 "EHLO mail-io1-f69.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725802AbgJHMPW (ORCPT ); Thu, 8 Oct 2020 08:15:22 -0400 Received: by mail-io1-f69.google.com with SMTP id m10so3530763ioq.0 for ; Thu, 08 Oct 2020 05:15:20 -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:in-reply-to:message-id:subject :from:to; bh=pIWW7+ADs4mL5pWYTBfL/vsBU9YaDtPFDDib5/UgpPE=; b=I625DV1QUbXfM13DE1nOS0T2ijE4IYWXDX6sgSGY/7vbdwTXLLJ+Ppln0nKkDoz2jW 031jjzsJGYtn/nisLfGV1EwUJofjsXJojDFQZklQP/L14Fxn9xIea0eMjFpMpMspfrbT ZbZPBvur/xxA6j3i4+Xzhm2BobaIjZiO4zr9V63GJ8UvewofAbr4XJ+wZohkOOQkkIsT s+pa9Ieizo31/QoSdvIR4ec16Chmpe7EJ/Fp/KaO0e3eN2iIDpEaXDKp4NjRvX0Vig3l JbnCGH4hcPzp/huSNH1C3LM3dUS9lxl7XKnZd5pvZdrYoAZF2kBjeQEoQ71Y+Dk2dEYl GdIg== X-Gm-Message-State: AOAM533luywaOT/ycmQhPr9OQCEh/s0z5xJ2DYbcK6RQjkNgPu6vKtJm Rf4ugZQP1zuNHHF1h6pGMp9OGURTDGsgeNd+58JPhfPmliIh X-Google-Smtp-Source: ABdhPJxL4+KEXadvLvkpXDJmnZMkeyEECK51lsd0+QRshE77s6Sq56UmHl1/jfTX3vzE5CfM07b4qDdFMW2lpZVnVKsCNhdZucXI MIME-Version: 1.0 X-Received: by 2002:a92:d4d0:: with SMTP id o16mr5040883ilm.152.1602159319952; Thu, 08 Oct 2020 05:15:19 -0700 (PDT) Date: Thu, 08 Oct 2020 05:15:19 -0700 In-Reply-To: <0000000000009caba805a9c7b840@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <00000000000023b29205b127c953@google.com> Subject: Re: INFO: rcu detected stall in __se_sys_mount From: syzbot To: fweisbec@gmail.com, linux-kernel@vger.kernel.org, mingo@kernel.org, syzkaller-bugs@googlegroups.com, tglx@linutronix.de Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org syzbot has found a reproducer for the following issue on: HEAD commit: c85fb28b Merge tag 'arm64-fixes' of git://git.kernel.org/p.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16b1804f900000 kernel config: https://syzkaller.appspot.com/x/.config?x=de7f697da23057c7 dashboard link: https://syzkaller.appspot.com/bug?extid=3f2db34df769d77edf8c compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11df5d4f900000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=157851e0500000 Bisection is inconclusive: the issue happens on the oldest tested release. bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12cedc5c900000 final oops: https://syzkaller.appspot.com/x/report.txt?x=11cedc5c900000 console output: https://syzkaller.appspot.com/x/log.txt?x=16cedc5c900000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+3f2db34df769d77edf8c@syzkaller.appspotmail.com rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): ------------[ cut here ]------------ WARNING: CPU: 1 PID: 7452 at kernel/sched/core.c:3013 rq_unlock kernel/sched/sched.h:1325 [inline] WARNING: CPU: 1 PID: 7452 at kernel/sched/core.c:3013 try_invoke_on_locked_down_task+0x12d/0x270 kernel/sched/core.c:3019 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 7452 Comm: syz-executor259 Not tainted 5.9.0-rc8-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+0x1d6/0x29e lib/dump_stack.c:118 panic+0x2c0/0x800 kernel/panic.c:231 __warn+0x227/0x250 kernel/panic.c:600 report_bug+0x1b1/0x2e0 lib/bug.c:198 handle_bug+0x42/0x80 arch/x86/kernel/traps.c:234 exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:254 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536 RIP: 0010:try_invoke_on_locked_down_task+0x12d/0x270 kernel/sched/sched.h:1325 Code: f8 48 c1 e8 03 42 8a 04 38 84 c0 0f 85 10 01 00 00 8b 74 24 18 48 89 ef e8 90 47 09 00 4c 89 ef e8 88 9b fd 06 e9 a4 00 00 00 <0f> 0b e9 2b ff ff ff 48 c7 c1 74 fb af 89 80 e1 07 80 c1 03 38 c1 RSP: 0018:ffffc90000da8c50 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffffffff896ff600 RCX: 0013916f856b3a00 RDX: ffffc90000da8d00 RSI: ffffffff8162d990 RDI: ffff88809027e480 RBP: ffffffff8162d990 R08: dffffc0000000000 R09: fffffbfff12df8f9 R10: fffffbfff12df8f9 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff896ff600 R14: ffff88809027e480 R15: dffffc0000000000 rcu_print_task_stall kernel/rcu/tree_stall.h:267 [inline] print_other_cpu_stall kernel/rcu/tree_stall.h:475 [inline] check_cpu_stall kernel/rcu/tree_stall.h:634 [inline] rcu_pending kernel/rcu/tree.c:3639 [inline] rcu_sched_clock_irq+0x12bc/0x1eb0 kernel/rcu/tree.c:2521 update_process_times+0x130/0x1b0 kernel/time/timer.c:1710 tick_sched_handle kernel/time/tick-sched.c:176 [inline] tick_sched_timer+0x25e/0x410 kernel/time/tick-sched.c:1328 __run_hrtimer kernel/time/hrtimer.c:1524 [inline] __hrtimer_run_queues+0x42d/0x930 kernel/time/hrtimer.c:1588 hrtimer_interrupt+0x373/0xd60 kernel/time/hrtimer.c:1650 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0xf0/0x260 arch/x86/kernel/apic/apic.c:1097 asm_call_irq_on_stack+0xf/0x20 __run_sysvec_on_irqstack arch/x86/include/asm/irq_stack.h:37 [inline] run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:89 [inline] sysvec_apic_timer_interrupt+0x94/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:strncasecmp+0x0/0x1c0 lib/string.c:44 Code: 2b 09 f2 48 01 c8 89 ce c1 e6 11 48 c1 e9 2f 09 f1 89 c6 31 ce 48 c1 e8 20 31 f0 31 d0 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc <55> 41 57 41 56 41 55 41 54 53 48 83 ec 10 48 85 d2 0f 84 80 01 00 RSP: 0018:ffffc90006357b98 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000007 RCX: dffffc0000000000 RDX: 0000000000000007 RSI: ffff88809752ce81 RDI: ffff88809eedc100 RBP: 0000000000000007 R08: ffffffff82dd8855 R09: ffffed1014220716 R10: ffffed1014220716 R11: 0000000000000000 R12: 00000000000009a0 R13: ffff88809eedc100 R14: 0000000000000007 R15: ffff8880a1103800 afs_lookup_cell_rcu+0x2bc/0x6f0 fs/afs/cell.c:88 afs_lookup_cell+0x246/0x14d0 fs/afs/cell.c:249 afs_parse_source fs/afs/super.c:290 [inline] afs_parse_param+0x526/0x790 fs/afs/super.c:326 vfs_parse_fs_param+0x1e5/0x460 fs/fs_context.c:117 vfs_parse_fs_string fs/fs_context.c:161 [inline] generic_parse_monolithic+0x230/0x350 fs/fs_context.c:201 do_new_mount fs/namespace.c:2871 [inline] path_mount+0x176c/0x29e0 fs/namespace.c:3192 do_mount fs/namespace.c:3205 [inline] __do_sys_mount fs/namespace.c:3413 [inline] __se_sys_mount+0x126/0x180 fs/namespace.c:3390 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x447a3a Code: b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 9d a3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 7a a3 fb ff c3 66 0f 1f 84 00 00 00 00 00 RSP: 002b:00007ffc915e4f78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007ffc915e4fc0 RCX: 0000000000447a3a RDX: 0000000020000000 RSI: 0000000020000040 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00007ffc915e4fc0 R09: 0000000000000004 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402240 R13: 00000000004022d0 R14: 0000000000000000 R15: 0000000000000000 Kernel Offset: disabled Rebooting in 86400 seconds..