rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (0 ticks this GP) idle=928c/1/0x4000000000000000 softirq=0/0 fqs=0 rcuc=10501 jiffies(starved)
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P17/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=43309, q=112 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 11875 Comm: syz.0.1409 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:num_possible_cpus include/linux/cpumask.h:1222 [inline]
RIP: 0010:mm_get_cid+0xab/0x130 kernel/sched/sched.h:3759
Code: 41 5c 41 5d 41 5e 41 5f 5d e9 41 86 43 09 cc 49 c7 c5 c8 84 01 8d 49 c1 ed 03 bd 00 00 00 80 eb 07 44 89 f0 f7 d8 71 d4 f3 90 <43> 0f b6 44 25 00 84 c0 75 41 44 8b 3d fc 8a 6f 0b 48 89 df 4c 89
RSP: 0018:ffffc900041877a8 EFLAGS: 00000887
RAX: 0000000080000000 RBX: ffff88803645cbd0 RCX: 1ffff11004eef2b4
RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffff88803645cbd0
RBP: 0000000080000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1006c8b94b R12: dffffc0000000000
R13: 1ffffffff1a03099 R14: 0000000080000000 R15: 0000000000000002
FS: 000055556d139500(0000) GS:ffff888126cee000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc27b75e440 CR3: 00000000573ec000 CR4: 00000000003526f0
Call Trace:
mm_cid_from_cpu kernel/sched/sched.h:3820 [inline]
mm_cid_schedin kernel/sched/sched.h:3870 [inline]
mm_cid_switch_to kernel/sched/sched.h:3886 [inline]
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x212a/0x5070 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
futex_do_wait kernel/futex/waitwake.c:358 [inline]
__futex_wait+0x1bd/0x3d0 kernel/futex/waitwake.c:687
futex_wait+0x104/0x360 kernel/futex/waitwake.c:715
do_futex+0x333/0x420 kernel/futex/syscalls.c:130
__do_sys_futex kernel/futex/syscalls.c:207 [inline]
__se_sys_futex+0x36f/0x400 kernel/futex/syscalls.c:188
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: 0033:0x7f1bcfe4f749
Code: Unable to access opcode bytes at 0x7f1bcfe4f71f.
RSP: 002b:00007ffdbb4f3dd8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00000000000d50e5 RCX: 00007f1bcfe4f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f1bd00a5fac
RBP: 0000000000000032 R08: 3fffffffffffffff R09: 00000005bb4f40cf
R10: 00007ffdbb4f3ed0 R11: 0000000000000246 R12: 00007f1bd00a5fac
R13: 00007ffdbb4f3ed0 R14: 00000000000d5117 R15: 00007ffdbb4f3ef0
task:pr/legacy state:R running task stack:27320 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x145f/0x5070 kernel/sched/core.c:6863
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7047
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
class_preempt_destructor include/linux/preempt.h:468 [inline]
__migrate_enable include/linux/sched.h:2389 [inline]
migrate_enable include/linux/sched.h:2429 [inline]
rt_spin_unlock+0xf1/0x200 kernel/locking/spinlock_rt.c:81
spin_unlock_irqrestore include/linux/spinlock_rt.h:122 [inline]
uart_port_unlock_irqrestore include/linux/serial_core.h:788 [inline]
serial8250_console_write+0x1029/0x1b40 drivers/tty/serial/8250/8250_port.c:3371
console_emit_next_record kernel/printk/printk.c:3109 [inline]
console_flush_one_record+0x685/0xb80 kernel/printk/printk.c:3215
legacy_kthread_func+0x16f/0x210 kernel/printk/printk.c:3674
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
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g43309 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=34080
rcu: rcu_preempt kthread starved for 10502 jiffies! g43309 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27576 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x145f/0x5070 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
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 31 Comm: kworker/1:0 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events __sched_core_put
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xe77/0x1250 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 12 9c 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 4d 97 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 31 97
RSP: 0018:ffffc90000a5f740 EFLAGS: 00000293
RAX: ffffffff81b415ef RBX: 1ffff11017108b21 RCX: ffff88801baf5ac0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000a5f880 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1db66cf R12: ffff8880b8845908
R13: dffffc0000000000 R14: ffff8880b893c8c0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888126dee000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f93d51e5d58 CR3: 000000000d3a8000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2711 [inline]
smp_text_poke_batch_finish+0xe98/0x1130 arch/x86/kernel/alternative.c:3004
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_disable_cpuslocked+0xc5/0x1a0 kernel/jump_label.c:240
static_key_disable+0x1a/0x20 kernel/jump_label.c:248
__sched_core_disable kernel/sched/core.c:477 [inline]
__sched_core_put+0xeb/0x110 kernel/sched/core.c:497
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
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
watchdog: BUG: soft lockup - CPU#1 stuck for 246s! [kworker/1:0:31]
Modules linked in:
irq event stamp: 1658198
hardirqs last enabled at (1658197): [] irqentry_exit+0x5e8/0x670 kernel/entry/common.c:219
hardirqs last disabled at (1658198): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1056
softirqs last enabled at (1605916): [] __local_bh_enable_ip+0x1a1/0x2c0 kernel/softirq.c:305
softirqs last disabled at (1605910): [] wg_packet_decrypt_worker+0xcd/0xce0 drivers/net/wireguard/receive.c:-1
CPU: 1 UID: 0 PID: 31 Comm: kworker/1:0 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events __sched_core_put
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xe77/0x1250 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 12 9c 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 4d 97 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 31 97
RSP: 0018:ffffc90000a5f740 EFLAGS: 00000293
RAX: ffffffff81b415ef RBX: 1ffff11017108b21 RCX: ffff88801baf5ac0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000a5f880 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1db66cf R12: ffff8880b8845908
R13: dffffc0000000000 R14: ffff8880b893c8c0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888126dee000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f93d51e5d58 CR3: 000000000d3a8000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2711 [inline]
smp_text_poke_batch_finish+0xe98/0x1130 arch/x86/kernel/alternative.c:3004
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_disable_cpuslocked+0xc5/0x1a0 kernel/jump_label.c:240
static_key_disable+0x1a/0x20 kernel/jump_label.c:248
__sched_core_disable kernel/sched/core.c:477 [inline]
__sched_core_put+0xeb/0x110 kernel/sched/core.c:497
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
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
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 11875 Comm: syz.0.1409 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:num_possible_cpus include/linux/cpumask.h:1222 [inline]
RIP: 0010:mm_get_cid+0xab/0x130 kernel/sched/sched.h:3759
Code: 41 5c 41 5d 41 5e 41 5f 5d e9 41 86 43 09 cc 49 c7 c5 c8 84 01 8d 49 c1 ed 03 bd 00 00 00 80 eb 07 44 89 f0 f7 d8 71 d4 f3 90 <43> 0f b6 44 25 00 84 c0 75 41 44 8b 3d fc 8a 6f 0b 48 89 df 4c 89
RSP: 0018:ffffc900041877a8 EFLAGS: 00000887
RAX: 0000000080000000 RBX: ffff88803645cbd0 RCX: 1ffff11004eef2b4
RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffff88803645cbd0
RBP: 0000000080000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1006c8b94b R12: dffffc0000000000
R13: 1ffffffff1a03099 R14: 0000000080000000 R15: 0000000000000002
FS: 000055556d139500(0000) GS:ffff888126cee000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc27b75e440 CR3: 00000000573ec000 CR4: 00000000003526f0
Call Trace:
mm_cid_from_cpu kernel/sched/sched.h:3820 [inline]
mm_cid_schedin kernel/sched/sched.h:3870 [inline]
mm_cid_switch_to kernel/sched/sched.h:3886 [inline]
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x212a/0x5070 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
futex_do_wait kernel/futex/waitwake.c:358 [inline]
__futex_wait+0x1bd/0x3d0 kernel/futex/waitwake.c:687
futex_wait+0x104/0x360 kernel/futex/waitwake.c:715
do_futex+0x333/0x420 kernel/futex/syscalls.c:130
__do_sys_futex kernel/futex/syscalls.c:207 [inline]
__se_sys_futex+0x36f/0x400 kernel/futex/syscalls.c:188
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: 0033:0x7f1bcfe4f749
Code: Unable to access opcode bytes at 0x7f1bcfe4f71f.
RSP: 002b:00007ffdbb4f3dd8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00000000000d50e5 RCX: 00007f1bcfe4f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f1bd00a5fac
RBP: 0000000000000032 R08: 3fffffffffffffff R09: 00000005bb4f40cf
R10: 00007ffdbb4f3ed0 R11: 0000000000000246 R12: 00007f1bd00a5fac
R13: 00007ffdbb4f3ed0 R14: 00000000000d5117 R15: 00007ffdbb4f3ef0