INFO: task hung in vcs_open (8)

Status: fixed on 2024/11/12 23:31
Subsystems: nilfs serial
[Documentation on labels]
Reported-by: syzbot+8a192e8d090fa9a31135@syzkaller.appspotmail.com
Fix commit: 08cfa12adf88 nilfs2: propagate directory read errors from nilfs_find_entry()
First crash: 719d, last: 659d
Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: INFO: rcu detected stall in sys_openat (log)
Repro: C syz .config
  
▶ ▼ Discussions (4)
Title Replies (including bot) Last reply
[PATCH] nilfs2: propagate directory read errors from nilfs_find_entry() 1 (1) 2024/10/04 03:35
[PATCH] nilfs2: add ratelimiting to nilfs2 message 4 (4) 2024/09/30 15:45
[syzbot] [serial?] INFO: task hung in vcs_open (8) 2 (4) 2024/09/28 03:53
[PATCH] nilfs2: add ratelimiting to nilfs2 message 5 (5) 2024/09/27 13:46
▶ ▼ Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in vcs_open (5) serial 1 2 1236d 1240d 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 437d 603d 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 1978d 1978d 0/29 auto-closed as invalid on 2021/05/22 19:06
upstream INFO: task hung in vcs_open serial 1 32 2149d 2282d 0/29 closed as dup on 2020/08/05 10:53
upstream INFO: task hung in vcs_open (2) serial 1 1 2129d 2129d 0/29 auto-closed as invalid on 2020/12/23 12:34
upstream INFO: task hung in vcs_open (7) serial 1 1 858d 858d 0/29 auto-obsoleted due to no activity on 2024/06/15 13:53
linux-4.19 INFO: task hung in vcs_open 1 11 2085d 2398d 0/1 auto-closed as invalid on 2021/03/07 01:31
upstream INFO: task hung in vcs_open (10) prio:low kernel 1 38 13d 55d 0/29 upstream: reported on 2026/05/29 18:45
upstream INFO: task hung in vcs_open (4) serial 1 2 1389d 1452d 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 2243d 2326d 0/1 auto-closed as invalid on 2020/09/30 10:12
upstream INFO: task hung in vcs_open (6) serial 1 2 1009d 1073d 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 1368d 1368d 0/1 auto-obsoleted due to no activity on 2023/02/22 05:12
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2024/09/27 01:38 19m lizhi.xu@windriver.com patch upstream log

Sample crash report:
INFO: task syz-executor199:5270 blocked for more than 147 seconds.
      Not tainted 6.11.0-syzkaller-08481-g88264981f208 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor199 state:D stack:27360 pid:5270  tgid:5255  ppid:5233   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5315 [inline]
 __schedule+0x1843/0x4ae0 kernel/sched/core.c:6674
 __schedule_loop kernel/sched/core.c:6751 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6766
 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2591
 ___down_common kernel/locking/semaphore.c:225 [inline]
 __down_common+0x346/0x7f0 kernel/locking/semaphore.c:246
 down+0x84/0xc0 kernel/locking/semaphore.c:63
 console_lock+0x145/0x1b0 kernel/printk/printk.c:2808
 vcs_open+0x5d/0xd0 drivers/tty/vt/vc_screen.c:763
 chrdev_open+0x521/0x600 fs/char_dev.c:414
 do_dentry_open+0x978/0x1460 fs/open.c:958
 vfs_open+0x3e/0x330 fs/open.c:1088
 do_open fs/namei.c:3774 [inline]
 path_openat+0x2c84/0x3590 fs/namei.c:3933
 do_filp_open+0x235/0x490 fs/namei.c:3960

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/09/22 17:01 upstream 88264981f208 6f888b75 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs INFO: task hung in vcs_open
2024/10/02 19:21 upstream e32cde8d2bd7 a4c7fd36 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in vcs_open
2024/09/22 12:11 upstream 88264981f208 6f888b75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in vcs_open
2024/08/07 16:10 upstream d4560686726f 7b2f2f35 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in vcs_open
2024/08/03 18:00 upstream 17712b7ea075 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in vcs_open
2024/09/20 19:31 upstream baeb9a7d8b60 6f888b75 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in vcs_open
2024/09/18 19:22 upstream 4a39ac5b7d62 c673ca06 .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.