rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=957c/1/0x4000000000000000 softirq=0/0 fqs=10 rcuc=10502 jiffies(starved)
rcu: 	(detected by 0, t=10502 jiffies, g=92929, q=171 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 29 Comm: ktimers/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
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 c3 cc cc cc cc cc 49 c7 c5 c8 b4 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 ec 4b 6f 0b 48 89 df 4c 89
RSP: 0018:ffffc90000a3f7c8 EFLAGS: 00000887
RAX: 0000000080000000 RBX: ffff8880396d6550 RCX: 1ffff11005175a44
RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffff8880396d6550
RBP: 0000000080000000 R08: ffff8880396d629f R09: 1ffff110072dac53
R10: dffffc0000000000 R11: ffffed10072dac54 R12: dffffc0000000000
R13: 1ffffffff1a03699 R14: 0000000080000000 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff888126e01000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000083e06000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 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+0x2153/0x50a0 kernel/sched/core.c:6863
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x16c/0x340 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 94 e7 14 10 <48> 3b 44 24 58 0f 85 e5 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90000a3fbe8 EFLAGS: 00000206
RAX: 0745c35573ba6a00 RBX: 0000000000000000 RCX: 0745c35573ba6a00
RDX: 0000000078796a83 RSI: ffffffff8cfe1b9c RDI: ffffffff8b3f56e0
RBP: ffffffff8ad4bc91 R08: ffffffff8ad4bc91 R09: ffffffff8d46b2e0
R10: 0000000000000100 R11: ffffffff818590f0 R12: 0000000000000000
R13: ffffffff8d46b2e0 R14: 0000000000000001 R15: 0000000000000246
 sched_submit_work kernel/sched/core.c:6901 [inline]
 schedule+0xb1/0x360 kernel/sched/core.c:6959
 smpboot_thread_fn+0x5bd/0xa60 kernel/smpboot.c:156
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10480 jiffies! g92929 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=68833
rcu: rcu_preempt kthread starved for 10481 jiffies! g92929 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:18616 pid:18    tgid:18    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x1480/0x50a0 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+0x599/0xb30 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: 44 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xec1/0x12b0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 f8 9d 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 33 99 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 17 99
RSP: 0018:ffffc90000b67620 EFLAGS: 00000293
RAX: ffffffff81b4cac9 RBX: 1ffff1101712854d RCX: ffff88801dac8000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000b677a0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1db664f R12: ffff8880b8942a68
R13: dffffc0000000000 R14: ffff8880b883c8c0 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff888126d01000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe59a33882b CR3: 000000000d3a8000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 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+0x5f9/0x1130 arch/x86/kernel/alternative.c:2921
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:874
 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+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
watchdog: BUG: soft lockup - CPU#0 stuck for 246s! [kworker/u8:2:44]
Modules linked in:
irq event stamp: 5248942
hardirqs last  enabled at (5248941): [<ffffffff8ad3a00d>] irqentry_exit+0x5dd/0x660 kernel/entry/common.c:219
hardirqs last disabled at (5248942): [<ffffffff8ad3887e>] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1056
softirqs last  enabled at (5198366): [<ffffffff81855963>] __local_bh_enable_ip+0x1b3/0x2e0 kernel/softirq.c:305
softirqs last disabled at (5198360): [<ffffffff8aa3d9c6>] local_bh_disable include/linux/bottom_half.h:20 [inline]
softirqs last disabled at (5198360): [<ffffffff8aa3d9c6>] spin_lock_bh include/linux/spinlock_rt.h:87 [inline]
softirqs last disabled at (5198360): [<ffffffff8aa3d9c6>] batadv_tt_req_purge net/batman-adv/translation-table.c:2583 [inline]
softirqs last disabled at (5198360): [<ffffffff8aa3d9c6>] batadv_tt_purge+0x4e6/0xa10 net/batman-adv/translation-table.c:3511
CPU: 0 UID: 0 PID: 44 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xec6/0x12b0 kernel/smp.c:877
Code: 89 ee 83 e6 01 31 ff e8 f8 9d 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 33 99 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 17 99 0b 00 eb e4 44
RSP: 0018:ffffc90000b67620 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff1101712854d RCX: ffff88801dac8000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000b677a0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1db664f R12: ffff8880b8942a68
R13: dffffc0000000000 R14: ffff8880b883c8c0 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff888126d01000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe59a33882b CR3: 000000000d3a8000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 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+0x5f9/0x1130 arch/x86/kernel/alternative.c:2921
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:874
 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+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 29 Comm: ktimers/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:_find_first_zero_bit+0x38/0xb0 lib/find_bit.c:149
Code: 85 f6 74 46 48 89 f3 49 89 fe 49 bc 00 00 00 00 00 fc ff df 48 89 f8 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 18 5b a5 fd <49> 8b 06 48 83 f8 ff 74 2b 45 31 ed 48 f7 d0 f3 48 0f bc c0 4c 01
RSP: 0018:ffffc90000a3f798 EFLAGS: 00000046
RAX: 1ffff110072dacaa RBX: 0000000000000002 RCX: 1ffff11005175a44
RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffff8880396d6550
RBP: 0000000080000000 R08: ffff8880396d629f R09: 1ffff110072dac53
R10: dffffc0000000000 R11: ffffed10072dac54 R12: dffffc0000000000
R13: 1ffffffff1a03699 R14: ffff8880396d6550 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff888126e01000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000083e06000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 find_first_zero_bit include/linux/find.h:393 [inline]
 __mm_get_cid kernel/sched/sched.h:3744 [inline]
 mm_get_cid+0xc7/0x130 kernel/sched/sched.h:3759
 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+0x2153/0x50a0 kernel/sched/core.c:6863
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x16c/0x340 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 94 e7 14 10 <48> 3b 44 24 58 0f 85 e5 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90000a3fbe8 EFLAGS: 00000206
RAX: 0745c35573ba6a00 RBX: 0000000000000000 RCX: 0745c35573ba6a00
RDX: 0000000078796a83 RSI: ffffffff8cfe1b9c RDI: ffffffff8b3f56e0
RBP: ffffffff8ad4bc91 R08: ffffffff8ad4bc91 R09: ffffffff8d46b2e0
R10: 0000000000000100 R11: ffffffff818590f0 R12: 0000000000000000
R13: ffffffff8d46b2e0 R14: 0000000000000001 R15: 0000000000000246
 sched_submit_work kernel/sched/core.c:6901 [inline]
 schedule+0xb1/0x360 kernel/sched/core.c:6959
 smpboot_thread_fn+0x5bd/0xa60 kernel/smpboot.c:156
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>