INFO: task kworker/u4:15:8461 blocked for more than 143 seconds.
Not tainted 6.4.0-rc2-next-20230515-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:15 state:D stack:26280 pid:8461 ppid:2 flags:0x00004000
Workqueue: events_unbound flush_to_ldisc
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5343 [inline]
__schedule+0x1d15/0x5790 kernel/sched/core.c:6669
schedule+0xde/0x1a0 kernel/sched/core.c:6745
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6804
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0xa3b/0x1350 kernel/locking/mutex.c:747
commit_echoes+0x4c/0x210 drivers/tty/n_tty.c:765
n_tty_receive_char+0x3b7/0x5b0 drivers/tty/n_tty.c:1419
n_tty_receive_buf_standard+0x930/0x2de0 drivers/tty/n_tty.c:1588
__receive_buf drivers/tty/n_tty.c:1612 [inline]
n_tty_receive_buf_common+0x3a8/0x1540 drivers/tty/n_tty.c:1710
tty_ldisc_receive_buf+0xa7/0x190 drivers/tty/tty_buffer.c:457
tty_port_default_receive_buf+0x72/0xa0 drivers/tty/tty_port.c:39
receive_buf drivers/tty/tty_buffer.c:515 [inline]
flush_to_ldisc+0x218/0x700 drivers/tty/tty_buffer.c:565
process_one_work+0x99a/0x15e0 kernel/workqueue.c:2407
worker_thread+0x67d/0x10c0 kernel/workqueue.c:2554
kthread+0x344/0x440 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>
Showing all locks held in the system:
1 lock held by kthreadd/2:
2 locks held by kworker/0:0/7:
#0: ffff888012470d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888012470d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff888012470d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline]
#0: ffff888012470d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:643 [inline]
#0: ffff888012470d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:670 [inline]
#0: ffff888012470d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 kernel/workqueue.c:2378
#1: ffffc900000c7db0 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x8b7/0x15e0 kernel/workqueue.c:2382
3 locks held by kworker/u4:0/10:
1 lock held by rcu_tasks_kthre/13:
#0: ffffffff8c798530 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:522
1 lock held by rcu_tasks_trace/14:
#0: ffffffff8c798230 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:522
1 lock held by khungtaskd/28:
#0: ffffffff8c799140 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x390 kernel/locking/lockdep.c:6559
1 lock held by khugepaged/34:
#0: ffffffff8c89c248 (lock#3){+.+.}-{3:3}, at: __lru_add_drain_all+0x62/0x6a0 mm/swap.c:852
1 lock held by jbd2/sda1-8/4420:
1 lock held by syslogd/4438:
2 locks held by udevd/4456:
2 locks held by getty/4752:
#0: ffff88814a633098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900015902f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2176
4 locks held by syz-fuzzer/5036:
2 locks held by syz-fuzzer/5038:
2 locks held by syz-fuzzer/5955:
1 lock held by syz-executor.5/5044:
3 locks held by syz-executor.4/5047:
#0: ffff88807ba95028 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x29/0x70 net/bluetooth/hci_core.c:552
#1: ffff88807ba94078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x306/0x1200 net/bluetooth/hci_sync.c:4928
#2: ffffffff8c7a4538 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:293 [inline]
#2: ffffffff8c7a4538 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x64a/0x770 kernel/rcu/tree_exp.h:992
1 lock held by syz-executor.3/5058:
3 locks held by kworker/u4:1/5074:
3 locks held by kworker/u4:2/5076:
3 locks held by kworker/u4:3/5082:
3 locks held by kworker/u4:6/5171:
3 locks held by kworker/u4:10/8394:
3 locks held by kworker/u4:13/8448:
6 locks held by kworker/u4:15/8461:
#0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline]
#0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:643 [inline]
#0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:670 [inline]
#0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 kernel/workqueue.c:2378
#1: ffffc9000342fdb0 ((work_completion)(&buf->work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x15e0 kernel/workqueue.c:2382
#2: ffff888012e420b8 (&buf->lock){+.+.}-{3:3}, at: flush_to_ldisc+0x44/0x700 drivers/tty/tty_buffer.c:537
#3: ffff88803e5a1098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x21/0x90 drivers/tty/tty_ldisc.c:263
#4: ffff88803e5a12e8 (&tty->termios_rwsem){++++}-{3:3}, at: n_tty_receive_buf_common+0x7f/0x1540 drivers/tty/n_tty.c:1673
#5: ffffc9000bea1380 (&ldata->output_lock){+.+.}-{3:3}, at: commit_echoes+0x4c/0x210 drivers/tty/n_tty.c:765
6 locks held by kworker/u4:17/8552:
3 locks held by kworker/u4:18/9097:
4 locks held by syz-executor.2/9209:
#0: ffff8880806ed028 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x29/0x70 net/bluetooth/hci_core.c:552
#1: ffff8880806ec078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x306/0x1200 net/bluetooth/hci_sync.c:4928
#2: ffffffff8e34be48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1831 [inline]
#2: ffffffff8e34be48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xc4/0x230 net/bluetooth/hci_conn.c:2484
#3: ffffffff8c7a4538 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:325 [inline]
#3: ffffffff8c7a4538 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3e8/0x770 kernel/rcu/tree_exp.h:992
3 locks held by kworker/u4:11/12523:
3 locks held by kworker/u4:19/13926:
3 locks held by kworker/u4:20/14261:
3 locks held by kworker/0:8/14940:
3 locks held by kworker/u4:12/16177:
2 locks held by kworker/0:12/16981:
#0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline]
#0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:643 [inline]
#0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:670 [inline]
#0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 kernel/workqueue.c:2378
#1: ffffc900063afdb0 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x15e0 kernel/workqueue.c:2382
3 locks held by kworker/1:6/20672:
2 locks held by kworker/0:13/21148:
3 locks held by syz-executor.1/23700:
#0: ffff88803d921028 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x29/0x70 net/bluetooth/hci_core.c:552
#1: ffff88803d920078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x306/0x1200 net/bluetooth/hci_sync.c:4928
#2: ffffffff8e34be48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1831 [inline]
#2: ffffffff8e34be48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xc4/0x230 net/bluetooth/hci_conn.c:2484
6 locks held by syz-executor.0/23945:
1 lock held by rm/23966:
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.4.0-rc2-next-20230515-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
nmi_cpu_backtrace+0x29c/0x350 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x2a4/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xe16/0x1090 kernel/hung_task.c:379
kthread+0x344/0x440 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 8552 Comm: kworker/u4:17 Not tainted 6.4.0-rc2-next-20230515-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
Workqueue: bat_events batadv_purge_orig
RIP: 0010:write_comp_data+0xc/0x90 kernel/kcov.c:230
Code: 00 75 10 65 48 8b 04 25 c0 bb 03 00 48 8b 80 00 16 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 65 8b 05 41 9d 7f 7e 49 89 f1 89 c6 <49> 89 d2 81 e6 00 01 00 00 49 89 f8 65 48 8b 14 25 c0 bb 03 00 a9
RSP: 0018:ffffc900000071a8 EFLAGS: 00000202
RAX: 0000000080000101 RBX: 0000000000000001 RCX: ffffffff884d8a0e
RDX: 0000000000000001 RSI: 0000000080000101 RDI: 0000000000000005
RBP: ffffffff8b646da0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 1c0000ff01000000 R12: 0000000000000001
R13: 0000000000000005 R14: 0000000000000003 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c01a9cd000 CR3: 0000000022435000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000003b DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
__sanitizer_cov_trace_switch+0x54/0x90 kernel/kcov.c:340
nf_hook_slow+0xde/0x1f0 net/netfilter/core.c:627
nf_hook+0x444/0x760 include/linux/netfilter.h:258
NF_HOOK include/linux/netfilter.h:301 [inline]
br_nf_forward_ip net/bridge/br_netfilter_hooks.c:637 [inline]
br_nf_forward_ip+0xb58/0x13c0 net/bridge/br_netfilter_hooks.c:578
nf_hook_entry_hookfn include/linux/netfilter.h:143 [inline]
nf_hook_slow+0xc9/0x1f0 net/netfilter/core.c:626
nf_hook+0x431/0x730 include/linux/netfilter.h:258
NF_HOOK include/linux/netfilter.h:301 [inline]
__br_forward+0x19a/0x570 net/bridge/br_forward.c:115
deliver_clone net/bridge/br_forward.c:131 [inline]
br_flood+0x383/0x470 net/bridge/br_forward.c:242
br_handle_frame_finish+0xf89/0x1de0 net/bridge/br_input.c:210
br_nf_hook_thresh+0x2fb/0x3f0 net/bridge/br_netfilter_hooks.c:1048
br_nf_pre_routing_finish_ipv6+0x695/0xf30 net/bridge/br_netfilter_ipv6.c:148
NF_HOOK include/linux/netfilter.h:303 [inline]
br_nf_pre_routing_ipv6+0x41b/0x830 net/bridge/br_netfilter_ipv6.c:178
br_nf_pre_routing+0xda4/0x1520 net/bridge/br_netfilter_hooks.c:508
nf_hook_entry_hookfn include/linux/netfilter.h:143 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:272 [inline]
br_handle_frame+0x9cb/0x1320 net/bridge/br_input.c:416
__netif_receive_skb_core+0xa10/0x3900 net/core/dev.c:5385
__netif_receive_skb_one_core+0xae/0x180 net/core/dev.c:5489
__netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5605
process_backlog+0x13e/0x6d0 net/core/dev.c:5933
__napi_poll+0xb3/0x520 net/core/dev.c:6496
napi_poll net/core/dev.c:6563 [inline]
net_rx_action+0x8e4/0xd00 net/core/dev.c:6696
__do_softirq+0x1d4/0x905 kernel/softirq.c:553
do_softirq.part.0+0x87/0xc0 kernel/softirq.c:454
</IRQ>
<TASK>
do_softirq kernel/softirq.c:446 [inline]
__local_bh_enable_ip+0x106/0x130 kernel/softirq.c:381
spin_unlock_bh include/linux/spinlock.h:395 [inline]
batadv_purge_orig_ref+0xeb8/0x1590 net/batman-adv/originator.c:1259
batadv_purge_orig+0x1b/0x60 net/batman-adv/originator.c:1272
process_one_work+0x99a/0x15e0 kernel/workqueue.c:2407
worker_thread+0x67d/0x10c0 kernel/workqueue.c:2554
kthread+0x344/0x440 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>