rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=63bc/1/0x4000000000000000 softirq=16372/16373 fqs=1
rcu: (detected by 0, t=10502 jiffies, g=13925, q=1646 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6103 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__run_hrtimer kernel/time/hrtimer.c:1746 [inline]
RIP: 0010:__hrtimer_run_queues+0x2ba/0xc30 kernel/time/hrtimer.c:1841
Code: db 0f 84 6c 04 00 00 e8 64 8e 12 00 eb 05 e8 5d 8e 12 00 48 8b 5c 24 18 4c 89 e7 e8 70 34 00 00 48 8b 44 24 48 42 80 3c 28 00 <74> 08 48 89 df e8 5c af 78 00 4c 89 23 48 8b 74 24 30 42 0f b6 04
RSP: 0018:ffffc90000a08d40 EFLAGS: 00000046
RAX: 1ffff110170e5081 RBX: ffff8880b8728408 RCX: ffff8880255d9e80
RDX: 0000000000010000 RSI: ffffffff8bc08340 RDI: ffffffff8bc08300
RBP: ffffc90000a08e90 R08: ffffffff8f822a77 R09: 1ffffffff1f0454e
R10: dffffc0000000000 R11: fffffbfff1f0454f R12: ffff8880792b7300
R13: dffffc0000000000 R14: 0000003090f8e400 R15: ffff8880b87283c0
FS: 000055555c5eb500(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2532c3117e CR3: 000000007e2be000 CR4: 00000000003526f0
Call Trace:
<IRQ>
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
</IRQ>
<TASK>
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+0x47/0x80 kernel/locking/spinlock.c:194
Code: f7 e8 cd 3a 42 f6 f7 c3 00 02 00 00 74 05 e8 20 67 6c f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 04 55 34 f6 65 8b 05 0d b8 23 07 85 c0 74 18 5b 41 5e c3 cc cc
RSP: 0018:ffffc900041cfad8 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000246 RCX: 0000000080000001
RDX: 0000000000000006 RSI: ffffffff8d792920 RDI: 0000000000000001
RBP: ffff88805cf6d900 R08: ffffffff8f822a77 R09: 1ffffffff1f0454e
R10: dffffc0000000000 R11: fffffbfff1f0454f R12: 1ffff1100674d580
R13: dffffc0000000000 R14: ffff88805cf6d8c0 R15: ffff888033a6ac08
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
devres_add drivers/base/devres.c:250 [inline]
devm_kmalloc+0x27e/0x300 drivers/base/devres.c:873
devm_kzalloc include/linux/device/devres.h:54 [inline]
led_allocate_basic net/bluetooth/leds.c:62 [inline]
hci_leds_init+0x39/0x180 net/bluetooth/leds.c:89
hci_register_dev+0x389/0x8b0 net/bluetooth/hci_core.c:2625
__vhci_create_device drivers/bluetooth/hci_vhci.c:451 [inline]
vhci_create_device+0x39c/0x650 drivers/bluetooth/hci_vhci.c:479
vhci_get_user drivers/bluetooth/hci_vhci.c:536 [inline]
vhci_write+0x3ce/0x4a0 drivers/bluetooth/hci_vhci.c:616
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5c9/0xb30 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2532b8e1c0
Code: 40 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d a1 d3 22 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89
RSP: 002b:00007ffdf1356058 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f2532b8e1c0
RDX: 0000000000000002 RSI: 00007ffdf135606a RDI: 00000000000000ca
RBP: 00007ffdf1356130 R08: 0000000000000000 R09: 00007f253391d6c0
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002
R13: 00007ffdf1356138 R14: 00007ffdf13563b8 R15: 0000000000000000
</TASK>
rcu: rcu_preempt kthread starved for 10480 jiffies! g13925 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:27576 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
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+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 5203 Comm: udevd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xcc5/0x1260 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 e4 97 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 8f 93 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 73 93
RSP: 0018:ffffc90003057640 EFLAGS: 00000293
RAX: ffffffff81b5644d RBX: 1ffff110170e8129 RCX: ffff8880745b0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003057768 R08: ffffffff8f822a77 R09: 1ffffffff1f0454e
R10: dffffc0000000000 R11: fffffbfff1f0454f R12: ffff8880b8740948
R13: dffffc0000000000 R14: ffff8880b863bb00 R15: 0000000000000001
FS: 00007f1535f74880(0000) GS:ffff888125e1f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005586ef27ca38 CR3: 0000000074f2a000 CR4: 00000000003526f0
Call Trace:
<TASK>
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
flush_tlb_mm_range+0x60a/0x1170 arch/x86/mm/tlb.c:1472
dup_mmap+0x15fa/0x1b80 mm/mmap.c:1866
dup_mm kernel/fork.c:1529 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1581
copy_process+0x165d/0x3950 kernel/fork.c:2221
kernel_clone+0x21e/0x820 kernel/fork.c:2651
__do_sys_clone kernel/fork.c:2792 [inline]
__se_sys_clone kernel/fork.c:2776 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2776
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f15358f1636
Code: 89 df e8 6d e8 f6 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 52 89 c5 85 c0 75 31 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffd573b0ec0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffd573b0ec8 RCX: 00007f15358f1636
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00005586ef273910 R08: 0000000000000000 R09: 00005586ef27b8e0
R10: 00007f1535f74b50 R11: 0000000000000246 R12: 00007ffd573b1280
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>