syzbot


INFO: task hung in ret_from_fork (3)

Status: auto-obsoleted due to no activity on 2024/02/08 01:02
Subsystems: serial
[Documentation on labels]
First crash: 175d, last: 175d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in ret_from_fork (2) fs 1 1278d 1278d 0/26 auto-closed as invalid on 2020/12/31 10:28
upstream INFO: task hung in ret_from_fork fs 4 2093d 2099d 0/26 auto-closed as invalid on 2019/02/22 10:29

Sample crash report:
INFO: task kworker/1:3:6433 blocked for more than 437 seconds.
      Not tainted 6.6.0-syzkaller-15758-ga12deb44f973 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:3     state:D stack:0     pid:6433  tgid:6433  ppid:2      flags:0x00000008
Call trace:
 __switch_to+0x1c8/0x2a0 arch/arm64/kernel/process.c:556
 context_switch kernel/sched/core.c:5376 [inline]
 __schedule+0xab0/0x2a8c kernel/sched/core.c:6688
 __schedule_loop kernel/sched/core.c:6763 [inline]
 schedule+0xd0/0x24c kernel/sched/core.c:6778
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6835
 kthread+0x1dc/0x300 kernel/kthread.c:381
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857

Showing all locks held in the system:
3 locks held by kworker/0:1/10:
1 lock held by kworker/R-mm_pe/12:
 #0: ffff8000865f4b88 (wq_pool_attach_mutex){+.+.}-{3:3}, at: worker_detach_from_pool+0x54/0x300 kernel/workqueue.c:2136
2 locks held by kworker/1:0/22:
1 lock held by khungtaskd/30:
 #0: ffff800086737c80 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x44/0x2d4 kernel/locking/lockdep.c:6607
3 locks held by kworker/u4:4/103:
1 lock held by kworker/R-dm_bu/1659:
 #0: ffff8000865f4b88 (wq_pool_attach_mutex){+.+.}-{3:3}, at: worker_attach_to_pool+0x3c/0x324 kernel/workqueue.c:2102
2 locks held by jbd2/vda-8/2919:
1 lock held by syslogd/2938:
1 lock held by klogd/2942:
1 lock held by udevd/2953:
2 locks held by getty/3072:
 #0: ffff0000141730a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80008951b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x93c/0xe9c drivers/tty/n_tty.c:2201
1 lock held by syz-fuzzer/3133:
3 locks held by syz-fuzzer/3282:
2 locks held by kworker/1:4/3140:
1 lock held by kworker/R-wg-cr/3175:
2 locks held by kworker/R-wg-cr/3176:
2 locks held by kworker/R-wg-cr/3177:
2 locks held by kworker/R-wg-cr/3179:
1 lock held by kworker/R-wg-cr/3182:
2 locks held by kworker/1:5/3278:
2 locks held by kworker/u4:1/3755:
2 locks held by kworker/1:2/5955:
2 locks held by kworker/u4:5/6404:
 #0: ffff000009821938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x594/0x143c kernel/workqueue.c:2605
 #1: ffff80008c1d7cd0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x594/0x143c kernel/workqueue.c:2605
2 locks held by kworker/u4:6/6444:
 #0: ffff000009821938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x594/0x143c kernel/workqueue.c:2605
 #1: ffff80008c317cd0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x594/0x143c kernel/workqueue.c:2605
1 lock held by udevd/6828:
1 lock held by syz-executor.0/6837:
 #0: ffff000016a0e810 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:802 [inline]
 #0: ffff000016a0e810 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: __sock_release+0x68/0x1f0 net/socket.c:658
4 locks held by syz-executor.0/6839:
1 lock held by modprobe/6841:
2 locks held by kworker/u4:6/6843:

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Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/11/10 01:02 upstream a12deb44f973 45e9b83e .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64 INFO: task hung in ret_from_fork
* Struck through repros no longer work on HEAD.