syzbot


INFO: task hung in writeback_inodes_sb

Status: auto-obsoleted due to no activity on 2023/04/12 11:41
Subsystems: arm
[Documentation on labels]
First crash: 982d, last: 982d

Sample crash report:
INFO: task syz-executor.2:3139 blocked for more than 143 seconds.
      Not tainted 6.1.0-rc8-syzkaller-33330-ga5541c0811a0 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2  state:D stack:0     pid:3139  ppid:1      flags:0x00000009
Call trace:
 __switch_to+0x180/0x298 arch/arm64/kernel/process.c:555
 context_switch kernel/sched/core.c:5209 [inline]
 __schedule+0x408/0x594 kernel/sched/core.c:6521
 schedule+0x64/0xa4 kernel/sched/core.c:6597
 wb_wait_for_completion+0x9c/0x12c fs/fs-writeback.c:191
 __writeback_inodes_sb_nr fs/fs-writeback.c:2628 [inline]
 writeback_inodes_sb_nr fs/fs-writeback.c:2645 [inline]
 writeback_inodes_sb+0xd4/0x11c fs/fs-writeback.c:2660
 sync_filesystem+0x50/0x134 fs/sync.c:54
 generic_shutdown_super+0x38/0x198 fs/super.c:474
 kill_block_super+0x30/0x78 fs/super.c:1428
 kill_f2fs_super+0x140/0x194 fs/f2fs/super.c:4612
 deactivate_locked_super+0x70/0xe8 fs/super.c:332
 deactivate_super+0xd0/0xd4 fs/super.c:363
 cleanup_mnt+0x184/0x1c0 fs/namespace.c:1186
 __cleanup_mnt+0x20/0x30 fs/namespace.c:1193
 task_work_run+0x100/0x148 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 do_notify_resume+0x174/0x1f0 arch/arm64/kernel/signal.c:1132
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
 el0_svc+0x9c/0x150 arch/arm64/kernel/entry-common.c:638
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/11:
 #0: ffff80000d4a4768 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x3c/0x450 kernel/rcu/tasks.h:507
1 lock held by rcu_tasks_trace/12:
 #0: ffff80000d4a4db8 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x3c/0x450 kernel/rcu/tasks.h:507
1 lock held by khungtaskd/27:
 #0: ffff80000d4a4640 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x4/0x48 include/linux/rcupdate.h:303
4 locks held by kworker/u4:5/1014:
2 locks held by getty/2758:
 #0: ffff0000c80e8898 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x28/0x58 drivers/tty/tty_ldisc.c:244
 #1: ffff80000f6be2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x19c/0x89c drivers/tty/n_tty.c:2177
1 lock held by syz-executor.2/3139:
 #0: ffff0001175f40e0 (&type->s_umount_key#49){+.+.}-{3:3}, at: deactivate_super+0xc8/0xd4 fs/super.c:362
3 locks held by kworker/u4:8/3467:
 #0: ffff0001fefcfe98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:537 [inline]
 #0: ffff0001fefcfe98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1354 [inline]
 #0: ffff0001fefcfe98 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1644 [inline]
 #0: ffff0001fefcfe98 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0xa4/0x594 kernel/sched/core.c:6438
 #1: ffff0001fefbeb88 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x280/0x380 kernel/sched/psi.c:909
 #2: ffff0001fefbf758 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:999 [inline]
 #2: ffff0001fefbf758 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x120/0x6d8 kernel/time/timer.c:1072

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


Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/12/21 10:47 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci a5541c0811a0 d3e76707 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in writeback_inodes_sb
* Struck through repros no longer work on HEAD.