syzbot


INFO: task hung in deactivate_super (3)

Status: upstream: reported on 2024/05/27 12:00
Reported-by: syzbot+4ae63a93dbe1440d6ba3@syzkaller.appspotmail.com
First crash: 20d, last: 20d
Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-49 INFO: task hung in deactivate_super 3 2165d 2183d 0/3 auto-closed as invalid on 2019/02/22 12:34
linux-6.1 INFO: task hung in deactivate_super 4 303d 352d 0/3 auto-obsoleted due to no activity on 2023/11/26 12:17
linux-4.14 INFO: task hung in deactivate_super 1 1875d 1875d 0/1 auto-closed as invalid on 2019/10/25 08:42
upstream INFO: task hung in deactivate_super exfat 36 1986d 2089d 0/27 closed as dup on 2018/10/27 13:17
upstream INFO: task hung in deactivate_super (2) reiserfs C inconclusive done 121 105d 445d 26/27 fixed on 2024/04/08 19:23
linux-5.15 INFO: task hung in deactivate_super 4 300d 388d 0/3 auto-obsoleted due to no activity on 2023/11/29 20:11
linux-6.1 INFO: task hung in deactivate_super (2) 1 123d 123d 0/3 auto-obsoleted due to no activity on 2024/05/24 05:27
linux-4.19 INFO: task hung in deactivate_super 4 477d 578d 0/1 upstream: reported on 2022/11/16 10:48

Sample crash report:
INFO: task syz-executor.0:7666 blocked for more than 143 seconds.
      Not tainted 6.1.92-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:0     pid:7666  ppid:1      flags:0x0000000d
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0xee4/0x1c98 kernel/sched/core.c:6558
 schedule+0xc4/0x170 kernel/sched/core.c:6634
 rwsem_down_write_slowpath+0xc80/0x156c kernel/locking/rwsem.c:1189
 __down_write_common kernel/locking/rwsem.c:1314 [inline]
 __down_write kernel/locking/rwsem.c:1323 [inline]
 down_write+0x84/0x88 kernel/locking/rwsem.c:1574
 deactivate_super+0xe8/0x110 fs/super.c:362
 cleanup_mnt+0x394/0x41c fs/namespace.c:1186
 __cleanup_mnt+0x20/0x30 fs/namespace.c:1193
 task_work_run+0x240/0x2f0 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 do_notify_resume+0x2148/0x3474 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/0x168 arch/arm64/kernel/entry-common.c:638
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
INFO: task syz-executor.4:8761 blocked for more than 143 seconds.
      Not tainted 6.1.92-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:0     pid:8761  ppid:7433   flags:0x0000000d
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0xee4/0x1c98 kernel/sched/core.c:6558
 schedule+0xc4/0x170 kernel/sched/core.c:6634
 jfs_flush_journal+0x5d8/0xd64 fs/jfs/jfs_logmgr.c:1564
 jfs_sync_fs+0x80/0xac fs/jfs/super.c:684
 dquot_quota_sync+0xc4/0x434 fs/quota/dquot.c:755
 quota_sync_one+0x114/0x188 fs/quota/quota.c:60
 iterate_supers+0x124/0x1dc fs/super.c:746
 quota_sync_all fs/quota/quota.c:69 [inline]
 __do_sys_quotactl fs/quota/quota.c:937 [inline]
 __se_sys_quotactl fs/quota/quota.c:916 [inline]
 __arm64_sys_quotactl+0x39c/0x7a0 fs/quota/quota.c:916
 __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:585

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffff800015a24e70 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/13:
 #0: ffff800015a25670 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:516
2 locks held by kworker/1:1/24:
 #0: ffff0000c0020938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
 #1: ffff800019f37c20 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
1 lock held by khungtaskd/28:
 #0: ffff800015a24ca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:349
2 locks held by getty/3986:
 #0: ffff0000d629f098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80001bcf02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1214 drivers/tty/n_tty.c:2188
1 lock held by syz-fuzzer/4221:
3 locks held by syz-executor.2/4765:
 #0: ffff0000d9b5d0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:552 [inline]
 #0: ffff0000d9b5d0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1d8/0x4a4 net/bluetooth/hci_core.c:2736
 #1: ffff0000d9b5c078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x39c/0xf6c net/bluetooth/hci_sync.c:5005
 #2: ffff800017f7ee88 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1805 [inline]
 #2: ffff800017f7ee88 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb0/0x27c net/bluetooth/hci_conn.c:2441
3 locks held by syz-executor.1/7425:
 #0: ffff0000f29c50b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:552 [inline]
 #0: ffff0000f29c50b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1d8/0x4a4 net/bluetooth/hci_core.c:2736
 #1: ffff0000f29c4078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x39c/0xf6c net/bluetooth/hci_sync.c:5005
 #2: ffff800017f7ee88 (hci_cb_list_lock){+.+.}

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/27 12:00 linux-6.1.y 88690811da69 761766e6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in deactivate_super
* Struck through repros no longer work on HEAD.