From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f208.google.com (mail-il1-f208.google.com [209.85.166.208]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8037F4B1E4F for ; Thu, 15 May 2025 04:05:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.208 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747281930; cv=none; b=aaZ+rLsH6C2/QS8eO07xYQ16Xa+Q5uyMNtYmMbdtsF8V/C7uoZ6roeZRXlYqYJ06mCupUsn5QzaSyydYAucSVMhdN24mu2Fsa0MqgXOwAHsNLUllUnpXarBRYGXGkdOryMtLvdUPbIX5fPZZfCeMBoo6ZAzwM7aJCQzh9wF9dV0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747281930; c=relaxed/simple; bh=WbaOjFqUgJEb48qtEbQ5iH6fpJ6aQ4/fjv+Msg5IOg4=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=Jm6y9YH3xeMZEebDK3c+WWvfOtWUJ7oNHM/kSgmFGJV9bUes//7GL1U8Ce5/RssHWX+NmjHLjimrvw3FGMKA7bW8gsCQgQpLzdLyZZo8k4wPpZ2KCIF/sfybRtYqq3afETuHSxZG6dsuu0PGYsB0UjPhZG5QC6n8CJBSaKyTwnQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.166.208 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-il1-f208.google.com with SMTP id e9e14a558f8ab-3d81bc9b763so8221245ab.0 for ; Wed, 14 May 2025 21:05:28 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1747281927; x=1747886727; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=+0bvqXSA1MWlQ0Tx3Jf5kQuYB868wAHWrRS3Kaz/YCg=; b=NU+szsH3GCefkXGpQbHkWPhQ7JS7RUy9VCLqXzUMoiwN7kNq+M1D09wGlPJNZwqFlw XnXlZVl+S8ssGUtkJwGWIUzPpvmOOaEiMXJORpdr+uSV/bxY6G9pCfpz3ZLS0w+vXcnm wUET37IAAiRa62EiRIoQxfB4c599Hn2g+AEyfHwI6Et2VootT8myb7TQQ60gAQu7/MYp VtTCeKgxf8M1dUUW6qeDsUs636YkrPXQNFOF7gmcqHGQ1Se/N4tyDCKV7NcmiOy1DK8z Msxg/TjmlPF1HFHRleSv82OwXBeNbZVH9oN0o21avLSFPOKser49KyK6A2UK/ImQM+cC HTgw== X-Forwarded-Encrypted: i=1; AJvYcCWTcfPX2D3wjlr8d2Vprn7eOOEV52hAZxIKnNVYRRR5k4zuVKWGbQ29jbruHYlbsYo20jJrWMMAPXIWyw==@vger.kernel.org X-Gm-Message-State: AOJu0YxRrWDc5Q7kowWjzGHjwMN+an/YhrRbF96LO1j0h246oo+cGEns bwu1uKa7bxA19VLqu6ql/5OmP8hjXdNIEQ+0ZJMRw08Ob/D9Fylyg6m+g+7IRrJZC8ykkTjl31Y iohK5qOGdI7X0cxfhPLbw4e5tvhT0vrSQs/fmCawgjkdFccr8YT6JkSM= X-Google-Smtp-Source: AGHT+IEQomtYcnnBJIZkcRc9OIMIxUoG7c54+xqdEXfZ+RPlMV4LGkSmmNCctNYX0JZdKfesrvteFQdXHiDOkXiemRU4yb1kLGJm Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:3e8d:b0:3d0:4e0c:2c96 with SMTP id e9e14a558f8ab-3db6f79a2demr72468195ab.2.1747281927482; Wed, 14 May 2025 21:05:27 -0700 (PDT) Date: Wed, 14 May 2025 21:05:27 -0700 In-Reply-To: <00000000000035b2ce06197bd027@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <68256807.a00a0220.104b28.0018.GAE@google.com> Subject: Re: [syzbot] [block?] INFO: task hung in bdev_open From: syzbot To: axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" syzbot has found a reproducer for the following issue on: HEAD commit: 9f35e33144ae x86/its: Fix build errors when CONFIG_MODULES=n git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=10639af4580000 kernel config: https://syzkaller.appspot.com/x/.config?x=bc44e21a0b824ef8 dashboard link: https://syzkaller.appspot.com/bug?extid=5c6179f2c4f1e111df11 compiler: Debian clang version 20.1.2 (++20250402124445+58df0ef89dd6-1~exp1~20250402004600.97), Debian LLD 20.1.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=115c4e70580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=166c2f68580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/0143554b1db5/disk-9f35e331.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/ccf3a30abae2/vmlinux-9f35e331.xz kernel image: https://storage.googleapis.com/syzbot-assets/6e205d989271/bzImage-9f35e331.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+5c6179f2c4f1e111df11@syzkaller.appspotmail.com INFO: task udevd:5194 blocked for more than 143 seconds. Not tainted 6.15.0-rc6-syzkaller-00052-g9f35e33144ae #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:24824 pid:5194 tgid:5194 ppid:1 task_flags:0x400140 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:746 bdev_open+0xe0/0xd30 block/bdev.c:945 blkdev_open+0x3a8/0x510 block/fops.c:652 do_dentry_open+0xdf3/0x1970 fs/open.c:956 vfs_open+0x3b/0x340 fs/open.c:1086 do_open fs/namei.c:3880 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4039 do_filp_open+0x1fa/0x410 fs/namei.c:4066 do_sys_openat2+0x121/0x1c0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1455 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdfe28a7407 RSP: 002b:00007ffefe105d00 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fdfe2f55880 RCX: 00007fdfe28a7407 RDX: 00000000000a0800 RSI: 000056326f6fe3e0 RDI: ffffffffffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 000056324ea0e100 R14: 0000000000000000 R15: 00007ffefe105f90 INFO: task syz-executor268:5876 blocked for more than 143 seconds. Not tainted 6.15.0-rc6-syzkaller-00052-g9f35e33144ae #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor268 state:D stack:27096 pid:5876 tgid:5872 ppid:5852 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:746 bdev_release+0x1a9/0x650 block/bdev.c:1128 blkdev_release+0x15/0x20 block/fops.c:660 __fput+0x44c/0xa70 fs/file_table.c:465 task_work_run+0x1d4/0x260 kernel/task_work.c:227 ptrace_notify+0x281/0x2c0 kernel/signal.c:2520 ptrace_report_syscall include/linux/ptrace.h:415 [inline] ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline] syscall_exit_work+0xc2/0x1d0 kernel/entry/common.c:173 syscall_exit_to_user_mode_prepare+0x6f/0xe0 kernel/entry/common.c:200 __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline] syscall_exit_to_user_mode+0x12/0x120 kernel/entry/common.c:218 do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4f6252f929 RSP: 002b:00007f4f624e5218 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f4f625b7328 RCX: 00007f4f6252f929 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f4f625b7320 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4f6258435c R13: 64626e2f7665642f R14: 0000200000000040 R15: 0000000080000000 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 2 locks held by kworker/u8:3/53: #0: ffff8880b8839b58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605 #1: ffff8880b8823b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x318/0x6d0 kernel/sched/psi.c:975 1 lock held by udevd/5194: #0: ffff888024977358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 2 locks held by getty/5587: #0: ffff8880303d60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002ffe2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by udevd/5861: #0: ffff888024977358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 1 lock held by syz-executor268/5876: #0: ffff888024977358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1128 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc6-syzkaller-00052-g9f35e33144ae #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at constant_test_bit arch/x86/include/asm/bitops.h:206 [inline] NMI backtrace for cpu 0 skipped: idling at arch_test_bit arch/x86/include/asm/bitops.h:238 [inline] NMI backtrace for cpu 0 skipped: idling at tif_test_bit include/linux/thread_info.h:192 [inline] NMI backtrace for cpu 0 skipped: idling at tif_need_resched include/linux/thread_info.h:208 [inline] NMI backtrace for cpu 0 skipped: idling at current_clr_polling_and_test include/linux/sched/idle.h:79 [inline] NMI backtrace for cpu 0 skipped: idling at default_idle_call+0x1b/0xb0 kernel/sched/idle.c:111 --- If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing.