rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7937/1:b..l P7931/1:b..l P5880/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=27117, q=593 ncpus=2)
task:syz-executor    state:R  running task     stack:20680 pid:5880  tgid:5880  ppid:5856   task_flags:0x400140 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__nr_to_section include/linux/mmzone.h:1941 [inline]
RIP: 0010:__pfn_to_section include/linux/mmzone.h:2079 [inline]
RIP: 0010:lookup_page_ext mm/page_ext.c:251 [inline]
RIP: 0010:page_ext_lookup+0x90/0x180 mm/page_ext.c:509
Code: 74 0c 48 c7 c7 00 80 b1 99 e8 8c e4 f4 ff 48 8b 05 d5 4a 83 17 48 85 c0 74 36 4e 8d 34 f0 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 <74> 08 4c 89 f7 e8 66 e4 f4 ff 4d 8b 36 4d 85 f6 74 1b 48 c1 eb 0f
RSP: 0018:ffffc9000457f688 EFLAGS: 00000246
RAX: 1ffff11047ffde80 RBX: 0000000000040b59 RCX: ffff8880319eda00
RDX: 0000000000000000 RSI: 0000000000001000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff822c796e
R10: 000000000000000f R11: ffffffff81ac3820 R12: 0000000000040b59
R13: dffffc0000000000 R14: ffff88823ffef400 R15: 0000000000001000
 page_ext_iter_begin include/linux/page_ext.h:132 [inline]
 __update_page_owner_free_handle+0x103/0x470 mm/page_owner.c:272
 __reset_page_owner+0x85/0x1f0 mm/page_owner.c:309
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895
 discard_slab mm/slub.c:2753 [inline]
 __put_partials+0x156/0x1a0 mm/slub.c:3218
 put_cpu_partial+0x17c/0x250 mm/slub.c:3293
 __slab_free+0x2d5/0x3c0 mm/slub.c:4550
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_kmalloc+0x22/0xb0 mm/kasan/common.c:396
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4365 [inline]
 __kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4377
 kmalloc_noprof include/linux/slab.h:909 [inline]
 tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x213/0x4b0 security/tomoyo/file.c:822
 security_inode_getattr+0x12f/0x330 security/security.c:2377
 vfs_getattr fs/stat.c:259 [inline]
 vfs_fstat fs/stat.c:281 [inline]
 vfs_fstatat+0xb1/0x170 fs/stat.c:373
 __do_sys_newfstatat fs/stat.c:542 [inline]
 __se_sys_newfstatat fs/stat.c:536 [inline]
 __x64_sys_newfstatat+0x116/0x190 fs/stat.c:536
 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: 0033:0x7f458cd8d3fa
RSP: 002b:00007f458d0dfce8 EFLAGS: 00000206 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f458cd8d3fa
RDX: 00007f458d0dfcf0 RSI: 00007f458ce4ede2 RDI: 0000000000000003
RBP: 00007f458d0dfcf0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000001000 R11: 0000000000000206 R12: 0000000000000078
R13: 0000000000000000 R14: 0000000000040cda R15: 00007f458d0dfe40
 </TASK>
task:syz.7.505       state:R  running task     stack:25128 pid:7931  tgid:7931  ppid:7439   task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7145
 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7169
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __local_bh_enable_ip+0x13e/0x1c0 kernel/softirq.c:414
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 __fib6_clean_all+0x23c/0x380 net/ipv6/ip6_fib.c:2317
 rt6_sync_down_dev net/ipv6/route.c:5005 [inline]
 rt6_disable_ip+0x120/0x720 net/ipv6/route.c:5010
 addrconf_ifdown+0x15d/0x1880 net/ipv6/addrconf.c:3853
 addrconf_notify+0x1bc/0x1010 net/ipv6/addrconf.c:-1
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers net/core/dev.c:2281 [inline]
 unregister_netdevice_many_notify+0x14d7/0x1ff0 net/core/dev.c:12166
 unregister_netdevice_many net/core/dev.c:12229 [inline]
 unregister_netdevice_queue+0x33c/0x380 net/core/dev.c:12073
 unregister_netdevice include/linux/netdevice.h:3385 [inline]
 __tun_detach+0xda4/0x1560 drivers/net/tun.c:621
 tun_detach drivers/net/tun.c:637 [inline]
 tun_chr_close+0x10a/0x1c0 drivers/net/tun.c:3433
 __fput+0x44c/0xa70 fs/file_table.c:468
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5b8c78ebe9
RSP: 002b:00007f5b8cadfb88 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000041177 RCX: 00007f5b8c78ebe9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f5b8c9b7da0 R08: 0000000000000001 R09: 000000058cadfe7f
R10: 0000001b33b20000 R11: 0000000000000246 R12: 00007f5b8c9b5fac
R13: 00007f5b8c9b5fa0 R14: ffffffffffffffff R15: 00007f5b8cadfca0
 </TASK>
task:syz.6.503       state:R  running task     stack:26888 pid:7937  tgid:7925  ppid:7438   task_flags:0x40044c flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7145
 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7169
 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+0x3f/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 zap_pte_range mm/memory.c:1756 [inline]
 zap_pmd_range mm/memory.c:1818 [inline]
 zap_pud_range mm/memory.c:1847 [inline]
 zap_p4d_range mm/memory.c:1868 [inline]
 unmap_page_range+0x3a79/0x4370 mm/memory.c:1889
 unmap_single_vma mm/memory.c:1932 [inline]
 unmap_vmas+0x399/0x580 mm/memory.c:1976
 exit_mmap+0x248/0xb50 mm/mmap.c:1280
 __mmput+0x118/0x420 kernel/fork.c:1130
 exit_mm+0x1da/0x2c0 kernel/exit.c:582
 do_exit+0x648/0x2300 kernel/exit.c:949
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
 get_signal+0x1286/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9398f8ebe9
RSP: 002b:00007f9399e100e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f93991b6098 RCX: 00007f9398f8ebe9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f93991b6098
RBP: 00007f93991b6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f93991b6128 R14: 00007f93992df940 R15: 00007f93992dfa28
 </TASK>
rcu: rcu_preempt kthread starved for 1742 jiffies! g27117 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:26792 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 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+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:unwind_next_frame+0x1734/0x2390 arch/x86/kernel/unwind_orc.c:648
Code: 21 c9 33 11 01 4c 89 f7 e8 89 0c 00 00 e9 f7 01 00 00 48 8b 54 24 08 48 8d 5a 02 48 83 c2 03 48 89 d8 48 c1 e8 03 0f b6 04 28 <84> c0 0f 85 19 0b 00 00 48 89 d0 48 c1 e8 03 0f b6 04 28 84 c0 0f
RSP: 0018:ffffc90000a07cf8 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: ffffffff90baae70 RCX: 0000000000000000
RDX: ffffffff90baae71 RSI: 0000000000000001 RDI: ffffc90000a07e28
RBP: dffffc0000000000 R08: ffffc90000a07e27 R09: 0000000000000000
R10: ffffc90000a07e18 R11: fffff52000140fc5 R12: ffffc90000a08a60
R13: ffffc90000a07e18 R14: ffffc90000a07dc8 R15: 1ffffffff21755ce
FS:  0000000000000000(0000) GS:ffff888125d1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000cd030 CR3: 00000000326aa000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:243 [inline]
 __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2417 [inline]
 slab_free mm/slub.c:4680 [inline]
 kmem_cache_free+0x18f/0x400 mm/slub.c:4782
 nft_synproxy_eval_v6+0x376/0x560 net/netfilter/nft_synproxy.c:91
 nft_synproxy_do_eval+0x3d7/0x570 net/netfilter/nft_synproxy.c:145
 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
 nft_do_chain+0x40c/0x1920 net/netfilter/nf_tables_core.c:285
 nft_do_chain_inet+0x25d/0x340 net/netfilter/nft_chain_filter.c:161
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
 nf_hook include/linux/netfilter.h:273 [inline]
 NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:316
 ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:500
 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
 __netif_receive_skb_one_core net/core/dev.c:5991 [inline]
 __netif_receive_skb+0xd3/0x380 net/core/dev.c:6104
 process_backlog+0x60e/0x14f0 net/core/dev.c:6456
 __napi_poll+0xc4/0x360 net/core/dev.c:7506
 napi_poll net/core/dev.c:7569 [inline]
 net_rx_action+0x707/0xe30 net/core/dev.c:7696
 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_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 53 e7 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d f3 86 0e 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c2
RAX: 31a1f97d77793e00 RBX: ffffffff819683c8 RCX: 31a1f97d77793e00
RDX: 0000000000000001 RSI: ffffffff8d9b77c5 RDI: ffffffff8be33680
RBP: ffffc90000197f20 R08: ffff8880b8732f9b R09: 1ffff110170e65f3
R10: dffffc0000000000 R11: ffffed10170e65f4 R12: ffffffff8fa38930
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110039d5b40
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:757
 default_idle_call+0x74/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:190 [inline]
 do_idle+0x1e8/0x510 kernel/sched/idle.c:330
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x147
 </TASK>