rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-....: (10056 ticks this GP) idle=887c/1/0x4000000000000000 softirq=10757/10767 fqs=44
rcu: hardirqs softirqs csw/system
rcu: number: 2056147 30 0
rcu: cputime: 43046 7693 16 ==> 50740(ms)
rcu: (t=10500 jiffies g=8033 q=1140 ncpus=2)
rcu: rcu_preempt kthread starved for 1989 jiffies! g8033 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:27752 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_timeout+0x160/0x280 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5079 Comm: kworker/u5:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: hci2 hci_conn_timeout
RIP: 0010:get_dep_list kernel/locking/lockdep.c:1554 [inline]
RIP: 0010:__bfs_next kernel/locking/lockdep.c:1686 [inline]
RIP: 0010:__bfs kernel/locking/lockdep.c:1736 [inline]
RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1844 [inline]
RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2804 [inline]
RIP: 0010:check_prev_add kernel/locking/lockdep.c:3138 [inline]
RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3253 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3869 [inline]
RIP: 0010:__lock_acquire+0x3201/0x7c80 kernel/locking/lockdep.c:5137
Code: 12 4c 89 f7 e8 80 ce 75 00 48 ba 00 00 00 00 00 fc ff df 4d 8b 36 4d 85 f6 74 66 49 83 c6 10 4c 89 f0 48 c1 e8 03 80 3c 10 00 <74> 12 4c 89 f7 e8 55 ce 75 00 48 ba 00 00 00 00 00 fc ff df 4d 8b
RSP: 0018:ffffc90010d7f4c0 EFLAGS: 00000046
RAX: 1ffffffff26ce8bb RBX: ffffffff937474a8 RCX: 0000000000000168
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff93753408
RBP: ffffc90010d7f708 R08: ffffc90010d7f697 R09: 0000000000000000
R10: ffffc90010d7f660 R11: fffff520021afed3 R12: ffffffff92ddf638
R13: 00000000000003fd R14: ffffffff936745d8 R15: ffff88802f4e29c8
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2625880990 CR3: 000000002db1c000 CR4: 00000000003506e0
Call Trace:
lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162
class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:522 [inline]
try_to_wake_up+0x60/0x1140 kernel/sched/core.c:4232
kick_pool+0x320/0x420 kernel/workqueue.c:1146
__queue_work+0xc46/0x1020 kernel/workqueue.c:1801
queue_work_on+0x121/0x1e0 kernel/workqueue.c:1835
queue_work include/linux/workqueue.h:562 [inline]
hci_cmd_sync_submit+0x285/0x2a0 net/bluetooth/hci_sync.c:745
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
CPU: 0 PID: 5906 Comm: syz.1.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__sanitizer_cov_trace_switch+0x81/0x120 kernel/kcov.c:349
Code: 00 00 00 b9 01 00 00 00 48 85 c0 0f 84 ae 00 00 00 41 57 41 56 41 54 53 48 8b 54 24 20 65 4c 8b 05 c4 1f 7e 7e 45 31 c9 eb 08 <49> ff c1 4c 39 c8 74 77 4e 8b 54 ce 10 65 44 8b 1d b2 1f 7e 7e 41
RSP: 0018:ffffc900000073b0 EFLAGS: 00000246
RAX: 0000000000000003 RBX: ffffffff8ed893f7 RCX: 0000000000000003
RDX: ffffffff813ab186 RSI: ffffffff8cb9e7b0 RDI: 0000000000000002
RBP: ffffc900000074f8 R08: ffff888021385a00 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000100 R12: ffffc900000074a8
R13: dffffc0000000000 R14: 0000000000000002 R15: ffffffff8ed893f6
FS: 00007f711d84c6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055bf438ee4c0 CR3: 0000000024e25000 CR4: 00000000003506f0
Call Trace:
unwind_next_frame+0xe46/0x2970 arch/x86/kernel/unwind_orc.c:581
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:328
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
slab_alloc_node mm/slub.c:3495 [inline]
kmem_cache_alloc_node+0x150/0x330 mm/slub.c:3540
__alloc_skb+0x108/0x2c0 net/core/skbuff.c:643
__netdev_alloc_skb+0x10c/0x500 net/core/skbuff.c:717
netdev_alloc_skb include/linux/skbuff.h:3272 [inline]
dev_alloc_skb include/linux/skbuff.h:3285 [inline]
hsr_init_skb+0xdc/0x580 net/hsr/hsr_device.c:266
send_hsr_supervision_frame+0x140/0xb90 net/hsr/hsr_device.c:309
hsr_announce+0x192/0x340 net/hsr/hsr_device.c:402
call_timer_fn+0x16e/0x530 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1752 [inline]
__run_timers+0x52d/0x7d0 kernel/time/timer.c:2023
run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:rcu_read_unlock_special+0x88/0x460 kernel/rcu/tree_plugin.h:698
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 69 4f 93 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90004d5f0a0 EFLAGS: 00000206
RAX: bf245f74cb760c00 RBX: 1ffff920009abe18 RCX: bf245f74cb760c00
RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6f80
RBP: ffffc90004d5f168 R08: ffffffff90d94507 R09: 1ffffffff21b28a0
R10: dffffc0000000000 R11: fffffbfff21b28a1 R12: ffffffff8cd35100
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
__rcu_read_unlock+0x7c/0xd0 kernel/rcu/tree_plugin.h:426
rcu_read_unlock include/linux/rcupdate.h:818 [inline]
is_bpf_text_address+0x27e/0x2a0 kernel/bpf/core.c:743
kernel_text_address+0xa0/0xd0 kernel/extable.c:125
__kernel_text_address+0xd/0x30 kernel/extable.c:79
unwind_get_return_address+0x5d/0xc0 arch/x86/kernel/unwind_orc.c:369
arch_stack_walk+0x11d/0x190 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45
__kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
__call_rcu_common kernel/rcu/tree.c:2721 [inline]
call_rcu+0x158/0x930 kernel/rcu/tree.c:2837
context_switch kernel/sched/core.c:5383 [inline]
__schedule+0x14da/0x44d0 kernel/sched/core.c:6699
preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866
preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890
preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
on_each_cpu_cond_mask+0x75/0x80 kernel/smp.c:1023
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:2222 [inline]
text_poke_bp_batch+0x318/0x930 arch/x86/kernel/alternative.c:2432
text_poke_flush arch/x86/kernel/alternative.c:2623 [inline]
text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2630
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_disable_cpuslocked+0xc5/0x1a0 kernel/jump_label.c:237
static_key_disable+0x1a/0x20 kernel/jump_label.c:245
tracepoint_remove_func kernel/tracepoint.c:417 [inline]
tracepoint_probe_unregister+0x6ad/0x930 kernel/tracepoint.c:551
trace_event_reg+0x153/0x260 kernel/trace/trace_events.c:-1
perf_trace_event_unreg+0xb3/0x1b0 kernel/trace/trace_event_perf.c:162
perf_trace_destroy+0x9e/0x140 kernel/trace/trace_event_perf.c:241
_free_event+0xb73/0xf30 kernel/events/core.c:5279
__do_sys_perf_event_open kernel/events/core.c:12950 [inline]
__se_sys_perf_event_open+0xfb7/0x1c20 kernel/events/core.c:12567
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f711c98f749
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:00007f711d84c038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f711cbe5fa0 RCX: 00007f711c98f749
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000040
RBP: 00007f711ca13f91 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f711cbe6038 R14: 00007f711cbe5fa0 R15: 00007ffd61484f38