syzbot


INFO: task hung in hfs_mdb_commit

Status: auto-obsoleted due to no activity on 2023/09/18 06:33
Reported-by: syzbot+612ff90eb230c1a4bb5d@syzkaller.appspotmail.com
First crash: 348d, last: 348d
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 115d 493d 26/26 fixed on 2024/03/20 11:33
linux-6.1 INFO: task hung in hfs_mdb_commit 1 366d 366d 0/3 auto-obsoleted due to no activity on 2023/08/31 05:50
linux-5.15 INFO: task hung in hfs_mdb_commit (2) origin:upstream C 3 3d11h 45d 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 484d 484d 0/1 upstream: reported C repro on 2023/01/25 02:58
linux-6.1 INFO: task hung in hfs_mdb_commit (2) 1 46d 46d 0/3 upstream: reported on 2024/04/07 10:21

Sample crash report:
INFO: task syz-executor.4:3554 blocked for more than 143 seconds.
      Not tainted 5.15.116-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:21048 pid: 3554 ppid:     1 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0x12c4/0x4590 kernel/sched/core.c:6372
 schedule+0x11b/0x1f0 kernel/sched/core.c:6455
 io_schedule+0x88/0x100 kernel/sched/core.c:8472
 bit_wait_io+0xe/0xc0 kernel/sched/wait_bit.c:209
 __wait_on_bit_lock+0xbf/0x1a0 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0x1d0/0x250 kernel/sched/wait_bit.c:117
 lock_buffer include/linux/buffer_head.h:402 [inline]
 hfs_mdb_commit+0xafb/0xfd0 fs/hfs/mdb.c:325
 hfs_sync_fs+0x11/0x20 fs/hfs/super.c:35
 sync_filesystem+0xe8/0x220 fs/sync.c:56
 generic_shutdown_super+0x6e/0x2c0 fs/super.c:448
 kill_block_super+0x7a/0xe0 fs/super.c:1405
 deactivate_locked_super+0xa0/0x110 fs/super.c:335
 cleanup_mnt+0x44e/0x500 fs/namespace.c:1143
 task_work_run+0x129/0x1a0 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:175
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x5d/0x250 kernel/entry/common.c:301
 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f6de8a345d7
RSP: 002b:00007ffe7d9b9f58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f6de8a345d7
RDX: 00007ffe7d9ba029 RSI: 000000000000000a RDI: 00007ffe7d9ba020
RBP: 00007ffe7d9ba020 R08: 00000000ffffffff R09: 00007ffe7d9b9df0
R10: 00005555566f9873 R11: 0000000000000246 R12: 00007f6de8a8dcdc
R13: 00007ffe7d9bb0e0 R14: 00005555566f9810 R15: 00007ffe7d9bb120
 </TASK>
INFO: task kworker/1:6:3598 blocked for more than 143 seconds.
      Not tainted 5.15.116-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:6     state:D stack:20064 pid: 3598 ppid:     2 flags:0x00004000
Workqueue: events_long flush_mdb
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0x12c4/0x4590 kernel/sched/core.c:6372
 schedule+0x11b/0x1f0 kernel/sched/core.c:6455
 io_schedule+0x88/0x100 kernel/sched/core.c:8472
 bit_wait_io+0xe/0xc0 kernel/sched/wait_bit.c:209
 __wait_on_bit_lock+0xbf/0x1a0 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0x1d0/0x250 kernel/sched/wait_bit.c:117
 lock_buffer include/linux/buffer_head.h:402 [inline]
 hfs_mdb_commit+0x117/0xfd0 fs/hfs/mdb.c:271
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2307
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2454
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91c5e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3261:
 #0: ffff888024803098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900024bb2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1da0 drivers/tty/n_tty.c:2147
1 lock held by syz-executor.4/3554:
 #0: ffff88809a2e60e0 (&type->s_umount_key#116){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:365
2 locks held by kworker/1:6/3598:
 #0: ffff888011c65538 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2280
 #1: ffffc900043cfd20 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2282
2 locks held by kworker/u4:16/5254:

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.116-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3611 Comm: kworker/u4:4 Not tainted 5.15.116-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
Workqueue: bat_events batadv_nc_worker
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0xc/0x60 kernel/kcov.c:197
Code: 89 fb e8 17 00 00 00 48 8b 3d 58 cc 63 0c 48 89 de 5b e9 07 84 48 00 cc cc cc cc cc cc cc 48 8b 04 24 65 48 8b 0d 64 76 82 7e <65> 8b 15 65 76 82 7e f7 c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74
RSP: 0018:ffffc9000447fbe8 EFLAGS: 00000293
RAX: ffffffff89f8e12a RBX: ffff88807ac6cb48 RCX: ffff888018a68000
RDX: 0000000000000000 RSI: ffffffff8a8b0f00 RDI: ffffffff8ad86000
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff1bc786e
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000169
R13: dffffc0000000000 R14: ffff88801ca74c80 R15: ffff88801aaa7680
FS:  0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcf6a6bd000 CR3: 0000000022a23000 CR4: 00000000003506e0
DR0: 0000000000000259 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 rcu_lock_acquire+0xa/0x30 include/linux/rcupdate.h:269
 rcu_read_lock include/linux/rcupdate.h:696 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
 batadv_nc_worker+0xc1/0x5b0 net/batman-adv/network-coding.c:723
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2307
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2454
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/06/10 06:33 linux-5.15.y 7349e40704a0 9018a337 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in hfs_mdb_commit
* Struck through repros no longer work on HEAD.