INFO: task hung in vcs_open (10)

Status: upstream: reported on 2026/05/29 18:45
Subsystems: kernel
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+99897fb26901360e1e8e@syzkaller.appspotmail.com
First crash: 358d, last: 2h12m
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
8c12c39a assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ INFO: task hung in vcs_open (10) 2026/05/21 09:22 2026/05/21 09:22 2026/05/21 10:29 cf874a1c
2d4c1ab4 repro INFO: task hung in vcs_open (10) 2026/03/10 13:35 2026/03/10 17:54 2026/03/10 18:19 86914af9
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [kernel?] INFO: task hung in vcs_open (10) 0 (1) 2026/05/29 18:45
Similar bugs (13)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in vcs_open (5) serial 1 2 1253d 1257d 0/29 auto-obsoleted due to no activity on 2023/06/04 04:45
upstream INFO: task hung in vcs_open (9) kernel 1 11 454d 620d 0/29 auto-obsoleted due to no activity on 2025/08/10 23:55
upstream INFO: task hung in vcs_open (3) serial 1 1 1995d 1995d 0/29 auto-closed as invalid on 2021/05/22 19:06
upstream INFO: task hung in vcs_open serial 1 32 2166d 2299d 0/29 closed as dup on 2020/08/05 10:53
upstream INFO: task hung in vcs_open (2) serial 1 1 2146d 2146d 0/29 auto-closed as invalid on 2020/12/23 12:34
upstream INFO: task hung in vcs_open (7) serial 1 1 875d 875d 0/29 auto-obsoleted due to no activity on 2024/06/15 13:53
linux-5.15 INFO: task hung in vcs_open 1 1 6d21h 6d21h 0/3 upstream: reported on 2026/08/03 15:31
linux-4.19 INFO: task hung in vcs_open 1 11 2102d 2415d 0/1 auto-closed as invalid on 2021/03/07 01:31
upstream INFO: task hung in vcs_open (4) serial 1 2 1406d 1469d 0/29 auto-obsoleted due to no activity on 2023/01/02 16:56
linux-4.14 INFO: task hung in vcs_open 1 3 2260d 2343d 0/1 auto-closed as invalid on 2020/09/30 10:12
upstream INFO: task hung in vcs_open (6) serial 1 2 1026d 1090d 0/29 auto-obsoleted due to no activity on 2024/01/17 08:03
linux-4.19 INFO: task hung in vcs_open (2) 1 1 1385d 1385d 0/1 auto-obsoleted due to no activity on 2023/02/22 05:12
upstream INFO: task hung in vcs_open (8) nilfs serial 1 syz, C inconclusive 7 676d 682d 28/29 fixed on 2024/11/12 23:31

Sample crash report:
INFO: task syz.5.6084:27448 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.6084      state:D stack:28424 pid:27448 tgid:27446 ppid:23431  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 schedule_timeout+0xc0/0x2c0 kernel/time/sleep_timeout.c:75
 ___down_common kernel/locking/semaphore.c:293 [inline]
 __down_common+0x3b7/0x850 kernel/locking/semaphore.c:318
 down+0x80/0xd0 kernel/locking/semaphore.c:100
 console_lock+0x58/0x90 kernel/printk/printk.c:2896
 class_console_lock_constructor include/linux/console.h:734 [inline]
 vcs_open+0x61/0xd0 drivers/tty/vt/vc_screen.c:746
 chrdev_open+0x4d9/0x600 fs/char_dev.c:411
 do_dentry_open+0x816/0x1380 fs/open.c:947
 vfs_open+0x3b/0x340 fs/open.c:1052
 do_open fs/namei.c:4700 [inline]
 path_openat+0x2e44/0x3830 fs/namei.c:4863
 do_file_open+0x23e/0x4a0 fs/namei.c:4892
 do_sys_openat2+0x115/0x200 fs/open.c:1368
 do_sys_open fs/open.c:1374 [inline]
 __do_sys_openat fs/open.c:1390 [inline]
 __se_sys_openat fs/open.c:1385 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1385
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7bc3b9e0d9
RSP: 002b:00007f7bc498b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f7bc3e25fa0 RCX: 00007f7bc3b9e0d9
RDX: 0000000000000080 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007f7bc3c35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7bc3e26038 R14: 00007f7bc3e25fa0 R15: 00007ffdc3631d88
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
 #0: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
 #0: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
1 lock held by khungtaskd/32:
 #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by getty/5362:
1 lock held by syz-executor/12041:
1 lock held by syz.2.4943/23021:
6 locks held by kworker/u8:37/23379:
2 locks held by kworker/u8:64/23407:
 #0: ffff88801b064140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #0: ffff88801b064140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
 #1: ffffc9000379fc40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #1: ffffc9000379fc40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
2 locks held by kworker/u8:65/23408:
 #0: ffff88801b064140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #0: ffff88801b064140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
 #1: ffffc9000378fc40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #1: ffffc9000378fc40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
6 locks held by syz.4.5619/25614:
1 lock held by syz.8.6405/28904:
1 lock held by syz.0.6406/28913:
1 lock held by dhcpcd-run-hook/28915:
4 locks held by modprobe/28918:
2 locks held by kworker/u8:64/28919:
1 lock held by syz-executor/28920:

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd7/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (57):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/10 11:08 upstream db2ddb871435 558388e4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in vcs_open
2026/08/09 10:08 upstream 06cf61899d64 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in vcs_open
2026/08/09 01:36 upstream a59f57e2aa12 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in vcs_open
2026/08/08 01:34 upstream 364465ab19de e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in vcs_open
2026/08/07 21:39 upstream 364465ab19de e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in vcs_open
2026/08/06 10:49 upstream 0d8395707651 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in vcs_open
2026/08/06 09:28 upstream 0d8395707651 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in vcs_open
2026/08/06 03:20 upstream 0d8395707651 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in vcs_open
2026/08/05 13:53 upstream c21bb4193868 b3eac40e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in vcs_open
2026/08/04 09:16 upstream c8e0d43058e6 a68cb31b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in vcs_open
2026/08/04 07:42 upstream c8e0d43058e6 a68cb31b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in vcs_open
2026/08/01 12:47 upstream 0131b508c0e2 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in vcs_open
2026/08/01 11:31 upstream 0131b508c0e2 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vcs_open
2026/08/01 00:52 upstream 8ba098e6b6ff 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in vcs_open
2026/07/31 14:40 upstream 8ba098e6b6ff 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in vcs_open
2026/07/28 12:56 upstream 62cc90241548 45ae1df4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in vcs_open
2026/07/11 11:07 upstream d96fcfe1b7f9 d78ea535 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vcs_open
2026/06/19 11:42 upstream 8c13415c8a43 d7ffd47b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in vcs_open
2026/06/16 23:03 upstream 6b5a2b7d9bc1 0e4b3e40 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vcs_open
2026/06/16 14:19 upstream 481329ec5b31 50bb0618 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vcs_open
2026/05/25 18:22 upstream e7ae89a0c97c c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in vcs_open
2026/05/22 02:54 upstream 6779b50faa56 e195359d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vcs_open
2026/04/26 15:29 upstream 897d54018cc9 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vcs_open
2026/04/19 08:54 upstream eb5249b12507 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vcs_open
2026/03/30 15:15 upstream 7aaa8047eafd 458630d8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vcs_open
2026/03/24 05:29 upstream c369299895a5 baf8bf12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in vcs_open
2026/03/16 16:33 upstream f338e7738378 64e21424 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vcs_open
2026/03/14 17:30 upstream 1c9982b49613 ee8d34d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vcs_open
2026/03/11 01:15 upstream b4f0dd314b39 4683d576 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vcs_open
2026/03/10 21:30 upstream 1f318b96cc84 4683d576 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in vcs_open
2026/03/09 22:54 upstream 1f318b96cc84 176bead5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vcs_open
2026/02/07 14:13 upstream 2687c848e578 f20fc9f9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vcs_open
2026/01/16 14:10 upstream 983d014aafb1 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in vcs_open
2026/01/14 19:48 upstream c537e12daeec d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in vcs_open
2026/01/03 02:21 upstream 9b0436804460 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vcs_open
2025/12/20 16:03 upstream dd9b004b7ff3 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vcs_open
2025/11/13 07:52 upstream e927c520e1ba 07e030de .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in vcs_open
2025/09/30 19:08 upstream 30d4efb2f5a5 65a0eece .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in vcs_open
2025/09/27 11:21 upstream fec734e8d564 001c9061 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in vcs_open
2025/08/22 16:08 upstream 3957a5720157 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in vcs_open
2025/08/21 03:47 upstream 41cd3fd15263 0b9605c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in vcs_open
2025/08/20 13:17 upstream b19a97d57c15 79512909 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in vcs_open
2025/08/17 11:40 upstream 99bade344cfa 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in vcs_open
2025/08/17 07:34 upstream 90d970cade8e 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in vcs_open
2026/08/04 22:48 upstream 848acc8ffe1b d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in vcs_open
2026/07/10 15:13 upstream a635d6748234 99e64375 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in vcs_open
2026/07/05 21:02 upstream f105f3631d51 fcece630 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in vcs_open
2026/06/29 05:59 upstream dc59e4fea9d8 fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in vcs_open
2026/06/18 09:08 upstream e771677c937d b62b3ded .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in vcs_open
2026/04/29 16:58 upstream 57b8e2d666a3 804ea88f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in vcs_open
2026/04/22 02:43 upstream 4ee64205ffaa 0b6ab7ec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in vcs_open
2026/04/13 01:47 upstream f5459048c38a 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in vcs_open
2026/03/30 09:41 upstream ac354b5cb04d 356bdfc9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in vcs_open
2025/12/29 06:06 upstream c875a6c32467 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in vcs_open
2025/12/10 23:24 upstream 0048fbb4011e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in vcs_open
* Struck through repros no longer work on HEAD.