syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=fff4/1/0x4000000000000000 softirq=15281/15282 fqs=0
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5850/1:b..l P5929/1:b..l
rcu: 	(detected by 1, t=10586 jiffies, g=9437, q=1300 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6065 Comm: kworker/0:6 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: wg-kex-wg2 wg_packet_handshake_receive_worker
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:151 [inline]
RIP: 0010:lock_release+0x16a/0x2d0 kernel/locking/lockdep.c:5892
Code: 19 0f 84 e6 00 00 00 48 c7 c7 1d 8a aa 8d e8 5d 68 de 09 b8 ff ff ff ff 65 0f c1 05 28 00 19 12 83 f8 01 0f 85 03 01 00 00 9c <58> f6 c4 02 0f 85 ee 00 00 00 41 f7 c5 00 02 00 00 74 01 fb 48 8b
RSP: 0018:ffffc90000007d30 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffff88802b2772c0 RCX: ffffc90000007d44
RDX: 0000000000000004 RSI: ffffffff8daa8a1d RDI: ffffffff8bf2b480
RBP: ffff88806b840800 R08: 0000000000000004 R09: 0000000000000002
R10: 0000000000000002 R11: ffff888025a42ff0 R12: ffffffff8980f56b
R13: 0000000000000002 R14: ffff888025a424c0 R15: 0000000000000005
FS:  0000000000000000(0000) GS:ffff8881248f4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005589db4fbbe0 CR3: 000000000e184000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 __raw_spin_unlock include/linux/spinlock_api_smp.h:141 [inline]
 _raw_spin_unlock+0x16/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 advance_sched+0x62b/0xc80 net/sched/sch_taprio.c:987
 __run_hrtimer kernel/time/hrtimer.c:1777 [inline]
 __hrtimer_run_queues+0x202/0xc40 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x3c0 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 e6 ce 1e f6 48 89 df e8 9e 21 1f f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 <bf> 01 00 00 00 e8 65 24 0f f6 65 8b 05 2e 89 37 08 85 c0 74 16 5b
RSP: 0018:ffffc90003207638 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffffffff9aea5f30 RCX: 0000000000000007
RDX: 0000000000000000 RSI: ffffffff8daceab2 RDI: ffffffff8bf2b480
RBP: 0000000000000282 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff9088bdd7 R11: ffff888025a42ff0 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88802a608000
 __debug_check_no_obj_freed lib/debugobjects.c:1108 [inline]
 debug_check_no_obj_freed+0x31f/0x600 lib/debugobjects.c:1129
 free_pages_prepare mm/page_alloc.c:1413 [inline]
 __free_frozen_pages+0x31a/0x1170 mm/page_alloc.c:2943
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4c/0xf0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 __kmalloc_cache_noprof+0x282/0x800 mm/slub.c:5771
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 keypair_create drivers/net/wireguard/noise.c:100 [inline]
 wg_noise_handshake_begin_session+0xe5/0xe80 drivers/net/wireguard/noise.c:827
 wg_packet_send_handshake_response+0x216/0x310 drivers/net/wireguard/send.c:96
 wg_receive_handshake_packet+0x247/0xbf0 drivers/net/wireguard/receive.c:154
 wg_packet_handshake_receive_worker+0x16d/0x380 drivers/net/wireguard/receive.c:213
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
task:kworker/0:3     state:R  running task     stack:25208 pid:5929  tgid:5929  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_power_efficient gc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x1139/0x6150 kernel/sched/core.c:6863
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:227 [inline]
RIP: 0010:nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:342 [inline]
RIP: 0010:gc_worker+0x2d5/0x16e0 net/netfilter/nf_conntrack_core.c:1548
Code: 00 00 48 c7 c7 a8 6a 89 90 e8 b7 c0 05 f8 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 85 b1 2a f8 58 48 85 db 0f 85 d4 0f 00 00 <e8> a6 b6 2a f8 8b 1d 70 25 f5 06 41 89 dc 31 ff 41 83 e4 01 44 89
RSP: 0018:ffffc90003507ad8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff89945069
RDX: ffff888025b1a4c0 RSI: ffffffff89945078 RDI: 0000000000000007
RBP: ffffffff9b0a48ec R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: ffff888025b1aff0 R12: ffff888025200000
R13: 0000000000040000 R14: dffffc0000000000 R15: 0000000000001770
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
task:udevd           state:R  running task     stack:26984 pid:5850  tgid:5850  ppid:5188   task_flags:0x40014c flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x1139/0x6150 kernel/sched/core.c:6863
 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7047
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 zap_pte_range mm/memory.c:1884 [inline]
 zap_pmd_range mm/memory.c:1946 [inline]
 zap_pud_range mm/memory.c:1975 [inline]
 zap_p4d_range mm/memory.c:1996 [inline]
 unmap_page_range+0x1047/0x43c0 mm/memory.c:2017
 unmap_single_vma+0x153/0x240 mm/memory.c:2059
 unmap_vmas+0x218/0x470 mm/memory.c:2101
 exit_mmap+0x1b0/0xb60 mm/mmap.c:1277
 __mmput+0x12a/0x410 kernel/fork.c:1173
 mmput+0x62/0x70 kernel/fork.c:1196
 exit_mm kernel/exit.c:581 [inline]
 do_exit+0x7d7/0x2bd0 kernel/exit.c:959
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1112
 __do_sys_exit_group kernel/exit.c:1123 [inline]
 __se_sys_exit_group kernel/exit.c:1121 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1121
 x64_sys_call+0x151c/0x1740 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f974b8f16c5
RSP: 002b:00007fffaf9b7bf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00005589db808f20 RCX: 00007f974b8f16c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 00005589db2c12c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffaf9b7c40 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10586 jiffies! g9437 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:28408 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x1139/0x6150 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6960
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 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: 1 UID: 0 PID: 5846 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:write_comp_data+0x11/0x90 kernel/kcov.c:246
Code: bc 09 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 49 89 d2 49 89 f8 49 89 f1 65 48 8b 15 57 cb f3 11 <65> 8b 05 68 cb f3 11 a9 00 01 ff 00 74 1d f6 c4 01 74 67 a9 00 00
RSP: 0018:ffffc9000404f698 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffff8880b84431e0 RCX: ffffffff81b29cb1
RDX: ffff888078ce24c0 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: ffff888078ce2ff0 R12: dffffc0000000000
R13: ffffed101708863d R14: 0000000000000001 R15: 0000000000000000
FS:  000055555b495500(0000) GS:ffff8881249f4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd732234ff8 CR3: 0000000073ec3000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 csd_lock_wait kernel/smp.c:342 [inline]
 smp_call_function_many_cond+0xe21/0x15e0 kernel/smp.c:877
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1043
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
 flush_tlb_mm_range+0x2f0/0x12c0 arch/x86/mm/tlb.c:1472
 tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:480 [inline]
 tlb_flush_mmu mm/mmu_gather.c:403 [inline]
 tlb_finish_mmu+0x3c9/0x7c0 mm/mmu_gather.c:497
 vms_clear_ptes+0x55a/0x790 mm/vma.c:1238
 vms_complete_munmap_vmas+0x1ca/0x970 mm/vma.c:1280
 do_vmi_align_munmap+0x446/0x7e0 mm/vma.c:1539
 do_vmi_munmap+0x204/0x3e0 mm/vma.c:1587
 __vm_munmap+0x196/0x380 mm/vma.c:3203
 __do_sys_munmap mm/mmap.c:1077 [inline]
 __se_sys_munmap mm/mmap.c:1074 [inline]
 __x64_sys_munmap+0x59/0x80 mm/mmap.c:1074
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd73138f7d7
Code: 00 00 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 0b 00 00 00 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:00007ffebf8f7e98 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 00007fd73222c000 RCX: 00007fd73138f7d7
RDX: 00007fd73138d830 RSI: 0000000000009000 RDI: 00007fd73222c000
RBP: 0000000000009000 R08: 00007ffebf8f7f30 R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000246 R12: 00000000000017ec
R13: 000055555b4a930c R14: 00007ffebf8f7f30 R15: 0000000000000000
 </TASK>