rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5902/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=11597, q=652 ncpus=2)
task:udevd state:R running task stack:25928 pid:5902 tgid:5902 ppid:5232 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7148
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7172
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0xfd/0x110 kernel/locking/spinlock.c:194
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
__wake_up_common_lock+0x190/0x1f0 kernel/sched/wait.c:127
sock_def_readable+0x1fb/0x550 net/core/sock.c:3551
unix_dgram_sendmsg+0xe08/0x1850 net/unix/af_unix.c:2309
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:729
sock_write_iter+0x279/0x360 net/socket.c:1182
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+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff97e6a7407
RSP: 002b:00007ffe7905ba40 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ff97ed9c880 RCX: 00007ff97e6a7407
RDX: 0000000000000000 RSI: 00007ffe7905bae7 RDI: 000000000000000a
RBP: 000000000000000a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ff97ed9c6e8
R13: 0000000000000000 R14: 0000000000000000 R15: 00005637f310eba0
rcu: rcu_preempt kthread starved for 10523 jiffies! g11597 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:26664 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7046 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7061
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+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5916 Comm: kworker/u9:2 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: hci3 hci_cmd_timeout
RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:146 [inline]
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/irqflags.h:158 [inline]
RIP: 0010:lock_is_held_type+0x125/0x190 kernel/locking/lockdep.c:5942
Code: 16 00 00 b8 ff ff ff ff 65 0f c1 05 35 4a 5c 07 83 f8 01 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c <41> f7 c4 00 02 00 00 74 01 fb 65 48 8b 05 f9 09 5c 07 48 3b 44 24
RSP: 0018:ffffc90000a08cf8 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 013d11564e7d1000
RDX: ffff88807acb5ac0 RSI: ffffffff8de9418e RDI: ffffffff8c050400
RBP: 00000000ffffffff R08: 0000000000000000 R09: ffffffff81aea350
R10: dffffc0000000000 R11: ffffffff8168ce40 R12: 0000000000000046
R13: ffff88807acb5ac0 R14: ffff8880b8727a98 R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffff8881258a7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 0000000074f22000 CR4: 00000000003526f0
Call Trace:
lock_is_held include/linux/lockdep.h:249 [inline]
__run_hrtimer kernel/time/hrtimer.c:1743 [inline]
__hrtimer_run_queues+0x284/0xc60 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5228
Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 ff b1 fc 09 e8 7a 4c 36 00 fb 4c 8b 65 c0 <49> 8d bc 24 58 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc9000430f638 EFLAGS: 00000282
RAX: 013d11564e7d1000 RBX: 0000000000000000 RCX: 013d11564e7d1000
RDX: 0000000000000006 RSI: ffffffff8dca0cff RDI: ffffffff8c050400
RBP: ffffc9000430f690 R08: ffffffff8fe53a37 R09: 1ffffffff1fca746
R10: dffffc0000000000 R11: fffffbfff1fca747 R12: ffff88807acb5ac0
R13: dffffc0000000000 R14: ffff88801dfc8000 R15: ffff8880b873ab58
context_switch kernel/sched/core.c:5363 [inline]
__schedule+0x17a0/0x4cc0 kernel/sched/core.c:6964
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7291
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:bt_err+0x4/0x160 net/bluetooth/lib.c:287
Code: d2 30 5b 0a cc e8 5c 47 58 0a 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <55> 48 89 e5 41 57 41 56 41 54 53 48 83 e4 e0 48 81 ec e0 00 00 00
RSP: 0018:ffffc9000430fa28 EFLAGS: 00000246
RAX: 1ffff1100fd99026 RBX: ffff88807ecc8978 RCX: ffff88807acb5ac0
RDX: 0000000000000000 RSI: ffff8881437b7cc0 RDI: ffffffff8cc90f00
RBP: ffffc9000430fc50 R08: ffffffff8fe53a37 R09: 1ffffffff1fca746
R10: dffffc0000000000 R11: ffffffff8a870de0 R12: dffffc0000000000
R13: ffff888027ed9218 R14: ffff88807ecc8000 R15: ffff88807ecc8130
hci_cmd_timeout+0xff/0x1e0 net/bluetooth/hci_core.c:1473
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245