syzbot


INFO: task hung in hci_conn_hash_flush

Status: auto-closed as invalid on 2021/09/10 15:42
Subsystems: bluetooth
[Documentation on labels]
First crash: 1020d, last: 1020d

Sample crash report:
INFO: task syz-executor.0:8432 blocked for more than 143 seconds.
      Not tainted 5.13.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:22408 pid: 8432 ppid:     1 flags:0x00004006
Call Trace:
 context_switch kernel/sched/core.c:4339 [inline]
 __schedule+0x916/0x23e0 kernel/sched/core.c:5147
 schedule+0xcf/0x270 kernel/sched/core.c:5226
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5285
 __mutex_lock_common kernel/locking/mutex.c:1036 [inline]
 __mutex_lock+0x7d4/0x10c0 kernel/locking/mutex.c:1104
 hci_disconn_cfm include/net/bluetooth/hci_core.h:1496 [inline]
 hci_conn_hash_flush+0xda/0x260 net/bluetooth/hci_conn.c:1608
 hci_dev_do_close+0x569/0x1110 net/bluetooth/hci_core.c:1785
 hci_unregister_dev+0x263/0x1130 net/bluetooth/hci_core.c:3999
 vhci_release+0x70/0xe0 drivers/bluetooth/hci_vhci.c:340
 __fput+0x288/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 exit_task_work include/linux/task_work.h:32 [inline]
 do_exit+0xbfc/0x2a60 kernel/exit.c:826
 do_group_exit+0x125/0x310 kernel/exit.c:923
 get_signal+0x47f/0x2150 kernel/signal.c:2835
 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:789
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x171/0x280 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:57
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x465f47
RSP: 002b:00007fff03ec5098 EFLAGS: 00000207 ORIG_RAX: 0000000000000054
RAX: 0000000000000000 RBX: 0000000000000065 RCX: 0000000000465f47
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fff03ec6230
RBP: 00007fff03ec5160 R08: 0000000000000000 R09: 0000000000547620
R10: 0000000000000231 R11: 0000000000000207 R12: 00000000004bee70
R13: 00007fff03ec6230 R14: 0000000001573810 R15: 00007fff03ec6270

Showing all locks held in the system:
3 locks held by systemd/1:
2 locks held by ksoftirqd/1/19:
1 lock held by khungtaskd/1642:
 #0: ffffffff8bf79320 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6333
1 lock held by in:imklog/8134:
 #0: ffff888027c22370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:974
3 locks held by kworker/0:3/8406:
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2247
 #1: ffffc9000191fda8 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2251
 #2: ffffffff8bf82528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 #2: ffffffff8bf82528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x27e/0x620 kernel/rcu/tree_exp.h:837
3 locks held by syz-executor.0/8432:
 #0: ffff888018a7cf48 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x111/0x1110 net/bluetooth/hci_core.c:1735
 #1: ffff888018a7c078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x26f/0x1110 net/bluetooth/hci_core.c:1772
 #2: ffffffff8d8b2528 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1496 [inline]
 #2: ffffffff8d8b2528 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xda/0x260 net/bluetooth/hci_conn.c:1608
1 lock held by syz-executor.1/8434:
 #0: ffffffff8d6a4ee8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:684 [inline]
 #0: ffffffff8d6a4ee8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x180 drivers/net/tun.c:3397
2 locks held by syz-executor.2/8436:
 #0: ffffffff8d6a4ee8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:684 [inline]
 #0: ffffffff8d6a4ee8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x180 drivers/net/tun.c:3397
 #1: ffffffff8bf82528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 #1: ffffffff8bf82528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x27e/0x620 kernel/rcu/tree_exp.h:837
1 lock held by syz-executor.4/8481:
 #0: ffffffff8d6a4ee8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:684 [inline]
 #0: ffffffff8d6a4ee8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x180 drivers/net/tun.c:3397
3 locks held by syz-executor.5/8639:
 #0: ffff888015994f48 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x111/0x1110 net/bluetooth/hci_core.c:1735
 #1: ffff888015994078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x26f/0x1110 net/bluetooth/hci_core.c:1772
 #2: ffffffff8d8b2528 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1496 [inline]
 #2: ffffffff8d8b2528 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xda/0x260 net/bluetooth/hci_conn.c:1608
2 locks held by kworker/0:8/9743:
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2247
 #1: ffffc9000c397da8 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2251
3 locks held by kworker/0:9/9782:
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2247
 #1: ffffc9000c4d7da8 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2251
 #2: ffffffff8d6a4ee8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xb/0x60 net/core/link_watch.c:250
2 locks held by kworker/0:14/15059:
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2247
 #1: ffffc900023afda8 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2251
2 locks held by kworker/0:19/15064:
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2247
 #1: ffffc9000241fda8 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2251
2 locks held by syz-executor.3/3367:
 #0: ffff888068e00f48 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x111/0x1110 net/bluetooth/hci_core.c:1735
 #1: ffff888068e00078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x26f/0x1110 net/bluetooth/hci_core.c:1772
2 locks held by kworker/0:0/3399:
 #0: ffff888011066538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888011066538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
 #0: ffff888011066538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 #0: ffff888011066538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: ffff888011066538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: ffff888011066538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2247
 #1: ffffc9000169fda8 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2251

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

NMI backtrace for cpu 0
CPU: 0 PID: 1642 Comm: khungtaskd Not tainted 5.13.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline]
 watchdog+0xd48/0xfb0 kernel/hung_task.c:294
 kthread+0x3b1/0x4a0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 19 Comm: ksoftirqd/1 Not tainted 5.13.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:pie_vars_init include/net/pie.h:107 [inline]
RIP: 0010:pie_calculate_probability+0x64e/0x7c0 net/sched/sch_pie.c:415
Code: c1 ea 03 80 3c 02 00 0f 85 62 01 00 00 48 89 ea 48 c7 43 30 ff ff ff ff 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 04 02 <84> c0 74 0c 3c 03 7f 08 48 89 ef e8 52 fd 7c fa c7 43 38 00 00 00
RSP: 0018:ffffc90000d97af0 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: ffff88807c285400 RCX: 0000000000000100
RDX: 1ffff1100f850a87 RSI: ffffffff873ce54d RDI: ffff88807c285430
RBP: ffff88807c285438 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff873ce4fe R11: 0000000000000000 R12: 0000000000000000
R13: ffff88806f7a3300 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7870750740 CR3: 0000000017047000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 fq_pie_timer+0x170/0x2a0 net/sched/sch_fq_pie.c:383
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1431
 expire_timers kernel/time/timer.c:1476 [inline]
 __run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1745
 __run_timers kernel/time/timer.c:1726 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1758
 __do_softirq+0x29b/0x9f6 kernel/softirq.c:559
 run_ksoftirqd kernel/softirq.c:921 [inline]
 run_ksoftirqd+0x2d/0x60 kernel/softirq.c:913
 smpboot_thread_fn+0x655/0x9e0 kernel/smpboot.c:165
 kthread+0x3b1/0x4a0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/06/12 15:36 net-old f4cdcae03f9c 1ba81399 .config console log report info ci-upstream-net-this-kasan-gce INFO: task hung in hci_conn_hash_flush
* Struck through repros no longer work on HEAD.