syzbot


INFO: task hung in hfs_mdb_commit

Status: auto-obsoleted due to no activity on 2023/08/31 05:50
Reported-by: syzbot+848fb6897ce6901bb1dc@syzkaller.appspotmail.com
First crash: 367d, last: 367d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in hfs_mdb_commit hfs C error done 25 116d 494d 26/26 fixed on 2024/03/20 11:33
linux-5.15 INFO: task hung in hfs_mdb_commit (2) origin:upstream C 3 4d02h 46d 0/3 upstream: reported C repro on 2024/04/08 12:18
linux-4.19 INFO: task hung in hfs_mdb_commit hfs C error 1 485d 485d 0/1 upstream: reported C repro on 2023/01/25 02:58
linux-5.15 INFO: task hung in hfs_mdb_commit 1 349d 349d 0/3 auto-obsoleted due to no activity on 2023/09/18 06:33
linux-6.1 INFO: task hung in hfs_mdb_commit (2) 1 47d 47d 0/3 upstream: reported on 2024/04/07 10:21

Sample crash report:
INFO: task kworker/0:6:4317 blocked for more than 143 seconds.
      Not tainted 6.1.29-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:6     state:D stack:0     pid:4317  ppid:2      flags:0x00000008
Workqueue: events_long flush_mdb
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0xee4/0x1c98 kernel/sched/core.c:6554
 schedule+0xc4/0x170 kernel/sched/core.c:6630
 io_schedule+0x8c/0x188 kernel/sched/core.c:8774
 bit_wait_io+0x1c/0xac kernel/sched/wait_bit.c:209
 __wait_on_bit_lock+0xcc/0x1e8 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0x194/0x21c kernel/sched/wait_bit.c:117
 wait_on_bit_lock_io include/linux/wait_bit.h:208 [inline]
 __lock_buffer+0x78/0xac fs/buffer.c:69
 lock_buffer include/linux/buffer_head.h:397 [inline]
 hfs_mdb_commit+0x9fc/0xf2c fs/hfs/mdb.c:325
 flush_mdb+0x6c/0x9c fs/hfs/super.c:66
 process_one_work+0x7ac/0x1404 kernel/workqueue.c:2289
 worker_thread+0x8e4/0xfec kernel/workqueue.c:2436
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860
INFO: task syz-executor.4:3759 blocked for more than 143 seconds.
      Not tainted 6.1.29-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:0     pid:3759  ppid:4262   flags:0x00000009
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0xee4/0x1c98 kernel/sched/core.c:6554
 schedule+0xc4/0x170 kernel/sched/core.c:6630
 schedule_timeout+0xb8/0x344 kernel/time/timer.c:1911
 do_wait_for_common+0x30c/0x468 kernel/sched/completion.c:85
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x48/0x60 kernel/sched/completion.c:138
 __flush_work+0x12c/0x1c0 kernel/workqueue.c:3073
 flush_work kernel/workqueue.c:3094 [inline]
 flush_delayed_work+0xe4/0x110 kernel/workqueue.c:3218
 hfs_file_fsync+0xec/0x148 fs/hfs/inode.c:683
 vfs_fsync_range+0x168/0x188 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2897 [inline]
 generic_file_write_iter+0x228/0x2b4 mm/filemap.c:3918
 call_write_iter include/linux/fs.h:2205 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x610/0x914 fs/read_write.c:584
 ksys_write+0x15c/0x26c fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:646
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffff800015774ef0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:510
1 lock held by rcu_tasks_trace/13:
 #0: ffff8000157756f0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:510
1 lock held by khungtaskd/28:
 #0: ffff800015774d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:305
2 locks held by getty/3980:
 #0: ffff0000c0922098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80001ca102f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1210 drivers/tty/n_tty.c:2177
3 locks held by syz-executor.3/4256:
2 locks held by kworker/0:6/4317:
 #0: ffff0000c0021538 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2262
 #1: ffff80001e3f7c20 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2264
3 locks held by syz-executor.4/3759:
 #0: ffff0000da21a5e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xd8/0x104 fs/file.c:1047
 #1: ffff0001290da460 (sb_writers#23){.+.+}-{0:0}, at: vfs_write+0x244/0x914 fs/read_write.c:580
 #2: ffff0001351be428 (&sb->s_type->i_mutex_key#28){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline]
 #2: ffff0001351be428 (&sb->s_type->i_mutex_key#28){+.+.}-{3:3}, at: hfs_file_fsync+0xa0/0x148 fs/hfs/inode.c:676

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


Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/05/23 05:50 linux-6.1.y fa74641fb6b9 4bce1a3e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in hfs_mdb_commit
* Struck through repros no longer work on HEAD.