rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (0 ticks this GP) idle=cb04/1/0x4000000000000000 softirq=166240/166240 fqs=0
rcu: (detected by 1, t=10502 jiffies, g=101249, q=335 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 21665 Comm: syz.4.4765 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:check_preemption_disabled+0x17/0x120 lib/smp_processor_id.c:14
Code: 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 48 83 ec 10 65 48 8b 05 be 54 43 07 48 89 44 24 08 <65> 8b 05 c6 54 43 07 65 8b 0d bb 54 43 07 f7 c1 ff ff ff 7f 74 23
RSP: 0018:ffffc90000007ba8 EFLAGS: 00000082
RAX: 2de98d1265e97000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8c035860 RDI: ffffffff8c035820
RBP: ffffffff81ae9ca2 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f88067 R12: 0000000000000000
R13: ffff8880b8627a98 R14: 0000000000000000 R15: 0000000000000001
FS: 00007f31e572b6c0(0000) GS:ffff8881259ff000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e51aff8 CR3: 0000000066552000 CR4: 00000000003526f0
Call Trace:
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:751
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0x5f/0x360 kernel/locking/lockdep.c:5831
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
_raw_spin_lock_irq+0xa2/0xf0 kernel/locking/spinlock.c:170
__run_hrtimer kernel/time/hrtimer.c:1765 [inline]
__hrtimer_run_queues+0x602/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
__sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 3b 01 47 f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 b3 ad 0f f6 65 8b 05 bc d7 40 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc9000419f9a0 EFLAGS: 00000206
RAX: 2de98d1265e97000 RBX: 0000000000000a06 RCX: 2de98d1265e97000
RDX: 0000000000000000 RSI: ffffffff8c035860 RDI: 0000000000000001
RBP: ffffc9000419fa30 R08: ffffffff8fc40337 R09: 1ffffffff1f88066
R10: dffffc0000000000 R11: fffffbfff1f88067 R12: dffffc0000000000
R13: 1ffff11006853009 R14: ffffffff99f393a8 R15: 1ffff92000833f34
__synchronize_srcu+0x293/0x3a0 kernel/rcu/srcutree.c:1442
hci_unregister_dev+0x148/0x510 net/bluetooth/hci_core.c:2702
hci_uart_tty_close+0x1b1/0x290 drivers/bluetooth/hci_ldisc.c:557
tty_ldisc_kill+0xa3/0x1a0 drivers/tty/tty_ldisc.c:613
tty_ldisc_release+0x1a4/0x200 drivers/tty/tty_ldisc.c:781
tty_release_struct+0x2a/0xd0 drivers/tty/tty_io.c:1681
tty_release+0xcb0/0x1640 drivers/tty/tty_io.c:1852
__fput+0x449/0xa70 fs/file_table.c:468
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x130 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f31e498ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f31e572b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000124
RAX: 0000000000000003 RBX: 00007f31e4bb5fa0 RCX: 00007f31e498ebe9
RDX: 0000000000080000 RSI: 0000000000000003 RDI: 0000000000000005
RBP: 00007f31e4a11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f31e4bb6038 R14: 00007f31e4bb5fa0 R15: 00007ffeed43e878
rcu: rcu_preempt kthread starved for 10502 jiffies! g101249 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:R running task stack:27520 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 21662 Comm: syz.3.4763 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xd33/0x12d0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 e6 5c 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 91 58 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 75 58
RSP: 0018:ffffc90004827760 EFLAGS: 00000293
RAX: ffffffff81b5365b RBX: 1ffff110170c8341 RCX: ffff888030891e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900048278e0 R08: ffffffff8fc40337 R09: 1ffffffff1f88066
R10: dffffc0000000000 R11: fffffbfff1f88067 R12: ffff8880b8641a08
R13: dffffc0000000000 R14: ffff8880b873b1c0 R15: 0000000000000000
FS: 00005555619ac500(0000) GS:ffff888125aff000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31106ff8 CR3: 0000000061422000 CR4: 00000000003526f0
DR0: 0000000000000001 DR1: 0000000000000002 DR2: 0000000000000008
DR3: 1000000100000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2653 [inline]
smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2863
__static_call_transform+0x4eb/0x750 arch/x86/kernel/static_call.c:111
arch_static_call_transform+0x98/0xc0 arch/x86/kernel/static_call.c:-1
__static_call_update+0xe4/0x5d0 kernel/static_call_inline.c:147
tracepoint_update_call kernel/tracepoint.c:271 [inline]
tracepoint_remove_func kernel/tracepoint.c:394 [inline]
tracepoint_probe_unregister+0x7e9/0x9b0 kernel/tracepoint.c:504
bpf_raw_tp_link_release+0x43/0x70 kernel/bpf/syscall.c:3655
bpf_link_free+0xed/0x330 kernel/bpf/syscall.c:3166
bpf_link_put_direct kernel/bpf/syscall.c:3209 [inline]
bpf_link_release+0x6b/0x80 kernel/bpf/syscall.c:3216
__fput+0x449/0xa70 fs/file_table.c:468
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x130 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5c5598ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc165e86e8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 000000000007d1e2 RCX: 00007f5c5598ebe9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f5c55bb7da0 R08: 0000000000000001 R09: 00000009165e89df
R10: 0000001b2ff20000 R11: 0000000000000246 R12: 00007f5c55bb5fac
R13: 00007f5c55bb5fa0 R14: ffffffffffffffff R15: 00007ffc165e8800