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INFO: task hung in rcu_state (2)

Status: auto-obsoleted due to no activity on 2024/06/23 10:24
Subsystems: serial
[Documentation on labels]
First crash: 308d, last: 308d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in rcu_state serial 1 562d 562d 0/28 auto-obsoleted due to no activity on 2023/10/13 03:49
upstream INFO: task hung in rcu_state (3) net 1 186d 186d 0/28 auto-obsoleted due to no activity on 2024/10/23 19:46

Sample crash report:
INFO: task syz-executor.0:12432 blocked for more than 143 seconds.
      Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:25112 pid:12432 tgid:12432 ppid:12398  flags:0x00000006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0x1781/0x49d0 kernel/sched/core.c:6736
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:1/8:
1 lock held by khungtaskd/29:
 #0: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #0: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
 #0: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614
3 locks held by kworker/1:2/783:
 #0: 
ffff888014c78948
 (
(wq_completion)events
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3229 [inline]
, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335
 #1: ffffc9000371fd00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
 #1: ffffc9000371fd00 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335
 #2: ffffffff8e1373b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
 #2: ffffffff8e1373b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x463/0x820 kernel/rcu/tree_exp.h:939
2 locks held by getty/4816:
 #0: 
ffff88802a37c0a0
 (
&tty->ldisc_sem
){++++}-{0:0}
, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: 
ffffc90002f162f0
 (
&ldata->atomic_read_lock
){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201
7 locks held by kworker/1:5/5157:
5 locks held by kworker/u8:9/11852:
4 locks held by kworker/u8:11/11854:
 #0: ffff888015acb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline]
 #0: ffff888015acb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335
 #1: ffffc900035dfd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
 #1: ffffc900035dfd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335
 #2: ffffffff8f36ef10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:591
 #3: ffff888059a39408 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_destruct+0x110/0x300 drivers/net/wireguard/device.c:250
3 locks held by syz-executor.0/12432:
 #0: ffff88805fa39060 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:552 [inline]
 #0: ffff88805fa39060 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1db/0x4e0 net/bluetooth/hci_core.c:2773
 #1: ffff88805fa38078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x48b/0x1050 net/bluetooth/hci_sync.c:5140
 #2: ffffffff8f4e41a8 (
hci_cb_list_lock
){+.+.}-{3:3}
, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2019 [inline]
, at: hci_conn_hash_flush+0xa6/0x240 net/bluetooth/hci_conn.c:2566
3 locks held by kworker/1:4/12495:
2 locks held by syz-executor.3/13976:
 #0: 
ffffffff8f37b588
 (
rtnl_mutex
){+.+.}-{3:3}
, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
, at: rtnetlink_rcv_msg+0x842/0x10d0 net/core/rtnetlink.c:6592
 #1: 
ffffffff8e1373b8
 (
rcu_state.exp_mutex
){+.+.}-{3:3}
, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
, at: synchronize_rcu_expedited+0x463/0x820 kernel/rcu/tree_exp.h:939

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

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xfb0/0xff0 kernel/hung_task.c:379
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 12495 Comm: kworker/1:4 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Workqueue: events uhid_device_add_worker
RIP: 0010:preempt_count_add+0x6/0x190 kernel/sched/core.c:5861
Code: 48 8b 3c 24 e8 ab 0b 90 00 eb 8c e9 ee fe ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 53 89 fb 48 c7 c0 60 66 4a 94 48 c1 e8 03 49 bf 00 00 00 00
RSP: 0018:ffffc90004186c28 EFLAGS: 00000002
RAX: 0000000000000002 RBX: 000002b525020af8 RCX: 0000000000000003
RDX: 00000000000002b5 RSI: ffffffff8bfdfee0 RDI: 0000000000000001
RBP: 00000000000003bd R08: ffffffff8528eb7e R09: 1ffff11003e86046
R10: dffffc0000000000 R11: ffffffff8b67b9d0 R12: dffffc0000000000
R13: 00000000000026f5 R14: 0000000000000899 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a1043e5950 CR3: 000000007ce10000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 delay_tsc+0x66/0xe0 arch/x86/lib/delay.c:79
 wait_for_lsr drivers/tty/serial/8250/8250_port.c:2087 [inline]
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3366 [inline]
 serial8250_console_write+0x10c2/0x1840 drivers/tty/serial/8250/8250_port.c:3444
 console_emit_next_record kernel/printk/printk.c:2907 [inline]
 console_flush_all+0x865/0xfd0 kernel/printk/printk.c:2973
 console_unlock+0x13b/0x4d0 kernel/printk/printk.c:3042
 vprintk_emit+0x5a6/0x770 kernel/printk/printk.c:2342
 dev_vprintk_emit+0x2ae/0x330 drivers/base/core.c:4864
 dev_printk_emit+0xdd/0x120 drivers/base/core.c:4875
 _dev_warn+0x122/0x170 drivers/base/core.c:4931
 hid_parser_main+0x71f/0xaa0 drivers/hid/hid-core.c:632
 hid_open_report+0xafa/0x14a0 drivers/hid/hid-core.c:1276
 hid_parse include/linux/hid.h:1118 [inline]
 hid_generic_probe+0x3d/0x90 drivers/hid/hid-generic.c:63
 __hid_device_probe drivers/hid/hid-core.c:2633 [inline]
 hid_device_probe+0x26e/0x4f0 drivers/hid/hid-core.c:2670
 really_probe+0x29e/0xc50 drivers/base/dd.c:658
 __driver_probe_device+0x1a2/0x3e0 drivers/base/dd.c:800
 driver_probe_device+0x50/0x430 drivers/base/dd.c:830
 __device_attach_driver+0x2d6/0x530 drivers/base/dd.c:958
 bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:457
 __device_attach+0x333/0x520 drivers/base/dd.c:1030
 bus_probe_device+0x189/0x260 drivers/base/bus.c:532
 device_add+0x8ff/0xca0 drivers/base/core.c:3639
 hid_add_device+0x3b6/0x520 drivers/hid/hid-core.c:2816
 uhid_device_add_worker+0x44/0xf0 drivers/hid/uhid.c:73
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/03/25 10:24 upstream fe46a7dd189e 0ea90952 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in rcu_state
* Struck through repros no longer work on HEAD.