syzbot

watchdog: BUG: soft lockup - CPU#0 stuck for 143s! [syz.5.506:8315]
Modules linked in:
irq event stamp: 13823309
hardirqs last  enabled at (13823308): [<ffffffff8b6e9424>] irqentry_exit+0x74/0x90 kernel/entry/common.c:310
hardirqs last disabled at (13823309): [<ffffffff8b6e7f6e>] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1050
softirqs last  enabled at (13823256): [<ffffffff8185bd4a>] __do_softirq kernel/softirq.c:613 [inline]
softirqs last  enabled at (13823256): [<ffffffff8185bd4a>] invoke_softirq kernel/softirq.c:453 [inline]
softirqs last  enabled at (13823256): [<ffffffff8185bd4a>] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
softirqs last disabled at (13823259): [<ffffffff8185bd4a>] __do_softirq kernel/softirq.c:613 [inline]
softirqs last disabled at (13823259): [<ffffffff8185bd4a>] invoke_softirq kernel/softirq.c:453 [inline]
softirqs last disabled at (13823259): [<ffffffff8185bd4a>] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
CPU: 0 UID: 0 PID: 8315 Comm: syz.5.506 Not tainted 6.16.0-rc6-syzkaller-gcd7c97f4584a #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:preempt_count_add+0x6/0x1a0 kernel/sched/core.c:5862
Code: 24 e8 ae 6a 92 00 eb 8c e9 f1 fe ff ff 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 53 49 bf 00 00 00 00 00 fc ff df 48 c7 c0 e0 52 ab 99 48 c1
RSP: 0018:ffffc90000007b50 EFLAGS: 00000246
RAX: ffffffff89768ad5 RBX: ffff88805bbc88b0 RCX: ffff888060869e00
RDX: 0000000000000100 RSI: ffffffff8be29f60 RDI: 0000000000000001
RBP: ffffc90000007c90 R08: ffffffff8fa1e8f7 R09: 1ffffffff1f43d1e
R10: dffffc0000000000 R11: ffffffff89768ac0 R12: 1ffff92000000f78
R13: ffff88805bbc8810 R14: ffff88805bbc8810 R15: ffff88805bbc8800
FS:  00007fc799b346c0(0000) GS:ffff888125c1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc799b13d58 CR3: 0000000077892000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __raw_spin_lock include/linux/spinlock_api_smp.h:132 [inline]
 _raw_spin_lock+0x12/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 mrp_join_timer+0x28/0x170 net/802/mrp.c:604
 call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747
 expire_timers kernel/time/timer.c:1798 [inline]
 __run_timers kernel/time/timer.c:2372 [inline]
 __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
 run_timer_base kernel/time/timer.c:2393 [inline]
 run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
 sysvec_irq_work+0xa3/0xc0 arch/x86/kernel/irq_work.c:17
 </IRQ>
 <TASK>
 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:738
RIP: 0010:instrument_atomic_read include/linux/instrumented.h:68 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
RIP: 0010:compound_order include/linux/mm.h:976 [inline]
RIP: 0010:pagetable_free include/linux/mm.h:2884 [inline]
RIP: 0010:pagetable_dtor_free+0x267/0x3b0 include/linux/mm.h:2982
Code: 85 e4 75 16 e8 4a b1 4b 00 eb 15 e8 43 b1 4b 00 e8 9e 1c fa 09 4d 85 e4 74 ea e8 34 b1 4b 00 fb 49 bc 00 00 00 00 00 fc ff df <48> 89 df be 08 00 00 00 e8 2c d7 ae 00 43 80 3c 27 00 74 08 48 89
RSP: 0018:ffffc900036cf5e0 EFLAGS: 00000283
RAX: ffffffff81746c8c RBX: ffffea0000cb6000 RCX: 0000000000080000
RDX: ffffc9001963d000 RSI: 0000000000015a3d RDI: 0000000000015a3e
RBP: ffffc900036cf690 R08: ffffffff8fa1e8f7 R09: 1ffffffff1f43d1e
R10: dffffc0000000000 R11: fffffbfff1f43d1f R12: dffffc0000000000
R13: 1ffff920006d9ebc R14: 0000000000000000 R15: 1ffffd4000196c00
 mm_free_pgd kernel/fork.c:541 [inline]
 __mmdrop+0xb5/0x460 kernel/fork.c:680
 mmdrop include/linux/sched/mm.h:55 [inline]
 mmdrop_sched include/linux/sched/mm.h:83 [inline]
 mmdrop_lazy_tlb_sched include/linux/sched/mm.h:110 [inline]
 finish_task_switch+0x3ee/0x950 kernel/sched/core.c:5290
 context_switch kernel/sched/core.c:5400 [inline]
 __schedule+0x16fd/0x4d00 kernel/sched/core.c:6786
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7109
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:debug_check_no_locks_freed+0x1f/0x1c0 kernel/locking/lockdep.c:6707
Code: 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 10 65 48 8b 05 26 b8 01 11 48 89 44 24 08 <65> 48 8b 1c 25 08 10 a0 92 83 3d 21 c2 03 0e 00 0f 84 af 00 00 00
RSP: 0018:ffffc900036cfac0 EFLAGS: 00000286
RAX: 843833386ec18300 RBX: ffff88807957cc40 RCX: 0000000000000003
RDX: ffffffff99b26220 RSI: 0000000000000040 RDI: ffff88807957cc40
RBP: 0000000000000003 R08: ffff88801b68f503 R09: 1ffff110036d1ea0
R10: dffffc0000000000 R11: ffffed10036d1ea1 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff99b26220 R15: ffffffff8b9937a0
 __raw_spin_lock_init+0x2b/0x100 kernel/locking/spinlock_debug.c:24
 init_file+0xcd/0x2f0 fs/file_table.c:162
 alloc_empty_file+0x6e/0x1d0 fs/file_table.c:238
 alloc_file fs/file_table.c:351 [inline]
 alloc_file_pseudo+0x13d/0x210 fs/file_table.c:380
 __anon_inode_getfile fs/anon_inodes.c:166 [inline]
 __anon_inode_getfd fs/anon_inodes.c:291 [inline]
 anon_inode_getfd+0xca/0x1b0 fs/anon_inodes.c:326
 map_create+0xf5d/0x1310 kernel/bpf/syscall.c:1541
 __sys_bpf+0x60f/0x870 kernel/bpf/syscall.c:6004
 __do_sys_bpf kernel/bpf/syscall.c:6132 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6130 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6130
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc798d8e9a9
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:00007fc799b34038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fc798fb5fa0 RCX: 00007fc798d8e9a9
RDX: 0000000000000048 RSI: 00002000000009c0 RDI: 0000000000000000
RBP: 00007fc798e10d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fc798fb5fa0 R15: 00007fffa4e88978
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted 6.16.0-rc6-syzkaller-gcd7c97f4584a #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0xf69/0x12d0 kernel/smp.c:885
Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 a0 6e 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 4b 6a 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 30 6a 0b
RSP: 0018:ffffc900001276a0 EFLAGS: 00000293
RAX: ffffffff81b4b390 RBX: ffff8880b873b200 RCX: ffff88801ceb8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000127800 R08: ffffffff8fa1e8f7 R09: 1ffffffff1f43d1e
R10: dffffc0000000000 R11: fffffbfff1f43d1f R12: 1ffff110170c838d
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8641c68
FS:  0000000000000000(0000) GS:ffff888125d1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4441a1bb6f CR3: 000000000df38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052
 on_each_cpu include/linux/smp.h:71 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2691 [inline]
 smp_text_poke_batch_finish+0x5e0/0x1100 arch/x86/kernel/alternative.c:2901
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:850
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>