rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5180/1:b..l P77/1:b..l P5818/1:b..l rcu: (detected by 0, t=10502 jiffies, g=41217, q=817 ncpus=2) task:syz-executor state:R running task stack:23416 pid:5818 tgid:5818 ppid:5803 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6908 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7235 irqentry_exit+0x17b/0x670 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__nr_to_section+0x7/0x100 include/linux/mmzone.h:1970 Code: e9 b0 fb ff ff 48 89 df e8 06 47 f3 ff e9 76 fb ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 54 55 53 48 89 fb <49> 89 dc 49 c1 ec 07 e8 5d c2 86 ff e9 a5 00 00 00 31 ed e8 51 c2 RSP: 0018:ffffc900044977a0 EFLAGS: 00000202 RAX: 1ffffffff1c23be5 RBX: 0000000000000010 RCX: ffffffff82806b11 RDX: dffffc0000000000 RSI: ffffffff8281fd80 RDI: 0000000000000010 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000004c201c9 R14: 0000000000000000 R15: 00000000033a04eb __pfn_to_section include/linux/mmzone.h:2114 [inline] lookup_page_ext+0x46/0x100 mm/page_ext.c:255 page_ext_iter_begin include/linux/page_ext.h:133 [inline] __update_page_owner_free_handle.isra.0+0xa4/0x4d0 mm/page_owner.c:284 __reset_page_owner+0x93/0x190 mm/page_owner.c:321 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 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:4542 [inline] slab_alloc_node mm/slub.c:4869 [inline] __do_kmalloc_node mm/slub.c:5262 [inline] __kmalloc_noprof+0x2b9/0x850 mm/slub.c:5275 kmalloc_noprof include/linux/slab.h:954 [inline] tomoyo_realpath_from_path+0xb6/0x690 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x276/0x460 security/tomoyo/file.c:827 security_inode_getattr+0x116/0x280 security/security.c:1869 vfs_getattr fs/stat.c:259 [inline] vfs_statx_path fs/stat.c:299 [inline] vfs_statx+0x11f/0x3f0 fs/stat.c:356 vfs_fstatat+0x77/0xe0 fs/stat.c:373 __do_sys_newfstatat+0x9d/0x120 fs/stat.c:538 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f491af9adda RSP: 002b:00007ffe27397198 EFLAGS: 00000286 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f491af9adda RDX: 00007ffe273971c0 RSI: 00007ffe27397250 RDI: 00000000ffffff9c RBP: 00007ffe27397250 R08: 00007ffe27398250 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000286 R12: 00007ffe273982e0 R13: 00007f491b031f90 R14: 00000000000703af R15: 00007ffe27398320 task:kswapd0 state:R running task stack:26408 pid:77 tgid:77 ppid:2 task_flags:0x220840 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6908 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7235 irqentry_exit+0x17b/0x670 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x19e/0x320 kernel/locking/lockdep.c:5893 Code: ff 65 0f c1 05 cb eb 28 12 83 f8 01 0f 85 3d 01 00 00 9c 58 f6 c4 02 0f 85 28 01 00 00 41 f7 c6 00 02 00 00 0f 85 de 00 00 00 <48> 8b 44 24 10 65 48 2b 05 1d a4 28 12 0f 85 63 01 00 00 48 83 c4 RSP: 0018:ffffc9000215ee70 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e7e75e0 RCX: ffffc9000215ee7c RDX: 0000000000000002 RSI: ffffffff8de4ec23 RDI: ffffffff8c1afaa0 RBP: ffffffff81b8019e R08: 0000000000000001 R09: 0000000000000007 R10: 0000000000000200 R11: 000000000001750d R12: ffff88801e364980 R13: ffffc9000215ef28 R14: 0000000000000202 R15: 0000000000000003 rcu_lock_release include/linux/rcupdate.h:322 [inline] rcu_read_unlock include/linux/rcupdate.h:881 [inline] class_rcu_destructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0x3c3/0x1ea0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556 __call_rcu_common.constprop.0+0xa5/0x9b0 kernel/rcu/tree.c:3131 security_inode_free+0xa4/0x170 security/security.c:1227 __destroy_inode+0x20a/0x740 fs/inode.c:372 destroy_inode+0x91/0x1c0 fs/inode.c:395 evict+0x599/0xad0 fs/inode.c:870 iput_final fs/inode.c:1966 [inline] iput.part.0+0x605/0xf50 fs/inode.c:2015 iput+0x35/0x40 fs/inode.c:1981 dentry_unlink_inode+0x2a1/0x490 fs/dcache.c:467 __dentry_kill+0x1d0/0x600 fs/dcache.c:670 shrink_kill fs/dcache.c:1147 [inline] shrink_dentry_list+0x180/0x5e0 fs/dcache.c:1174 prune_dcache_sb+0xea/0x150 fs/dcache.c:1256 super_cache_scan+0x328/0x550 fs/super.c:223 do_shrink_slab+0x416/0x11e0 mm/shrinker.c:437 shrink_slab+0x171/0x12b0 mm/shrinker.c:664 shrink_one+0x398/0x7f0 mm/vmscan.c:4928 shrink_many mm/vmscan.c:4989 [inline] lru_gen_shrink_node mm/vmscan.c:5067 [inline] shrink_node+0x26a2/0x3e20 mm/vmscan.c:6047 kswapd_shrink_node mm/vmscan.c:6894 [inline] balance_pgdat+0xbb7/0x1ca0 mm/vmscan.c:7070 kswapd+0x556/0xba0 mm/vmscan.c:7343 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:udevd state:R running task stack:23688 pid:5180 tgid:5180 ppid:1 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6908 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7235 irqentry_exit+0x17b/0x670 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:222 [inline] RIP: 0010:unwind_next_frame+0x1ce/0x1ea0 arch/x86/kernel/unwind_orc.c:510 Code: 25 02 00 00 49 81 ff 00 9e 93 8b 0f 83 18 02 00 00 8b 35 f5 6e 5a 0c 4c 89 f8 48 2d 00 00 00 81 48 c1 e8 08 8d 56 ff 41 89 c3 <39> d0 0f 83 8a 15 00 00 48 ba 00 00 00 00 00 fc ff df 89 c1 48 8d RSP: 0018:ffffc900035572c0 EFLAGS: 00000206 RAX: 000000000001b881 RBX: 0000000000000001 RCX: 1ffff920006aae6f RDX: 00000000000a939e RSI: 00000000000a939f RDI: ffffffff8e1268e8 RBP: ffffc90003557378 R08: 000000006ed9bd88 R09: 0000000000000007 R10: 0000000000000200 R11: 000000000001b881 R12: ffffc90003557380 R13: ffffc90003557330 R14: ffffc90003557365 R15: ffffffff82b88145 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x162/0x1e0 mm/page_owner.c:165 __reset_page_owner+0x84/0x190 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 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:4542 [inline] slab_alloc_node mm/slub.c:4869 [inline] kmem_cache_alloc_lru_noprof+0x246/0x6e0 mm/slub.c:4888 alloc_inode+0x183/0x250 fs/inode.c:349 iget_locked+0x1d9/0x6d0 fs/inode.c:1480 kernfs_get_inode+0x46/0x470 fs/kernfs/inode.c:253 kernfs_iop_lookup+0x1a7/0x2d0 fs/kernfs/dir.c:1241 __lookup_slow+0x251/0x460 fs/namei.c:1916 lookup_slow+0x50/0x70 fs/namei.c:1933 walk_component fs/namei.c:2279 [inline] link_path_walk+0x1377/0x1cc0 fs/namei.c:2647 path_openat+0x1be/0x31a0 fs/namei.c:4826 do_file_open+0x20e/0x430 fs/namei.c:4859 do_sys_openat2+0x10d/0x1e0 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc4982a7407 RSP: 002b:00007fff64e67ea0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fc498996880 RCX: 00007fc4982a7407 RDX: 0000000000080000 RSI: 00007fff64e68020 RDI: ffffffffffffff9c RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055afd3d907f5 R13: 000055afd3d907f5 R14: 0000000000000001 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10624 jiffies! g41217 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:27736 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6908 __schedule_loop kernel/sched/core.c:6990 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7005 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 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 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:mark_lock+0x9c/0xa20 kernel/locking/lockdep.c:4722 Code: 01 00 00 00 48 8b 54 24 68 65 48 2b 15 75 dd 28 12 0f 85 ea 07 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc 46 22 03 74 8d 41 be 00 02 00 00 bb 09 00 00 00 eb 8e 8b 05 fb RSP: 0018:ffffc90000a07e00 EFLAGS: 00000046 RAX: 0000000000000003 RBX: 0000000000000008 RCX: 0000000000000003 RDX: 0000000000000008 RSI: ffff88801e6a3090 RDI: ffff88801e6a24c0 RBP: ffffc90000a07ea0 R08: 0000000000000000 R09: 0000000000000007 R10: 0000000000000003 R11: 0000000000000000 R12: ffff88801e6a3090 R13: ffff88801e6a24c0 R14: 0000000000000003 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff888124447000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fffe8037ac0 CR3: 0000000078112000 CR4: 00000000003526f0 Call Trace: mark_usage kernel/locking/lockdep.c:4674 [inline] __lock_acquire+0x4a5/0x2630 kernel/locking/lockdep.c:5191 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1cf/0x380 kernel/locking/lockdep.c:5825 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4542 [inline] slab_alloc_node mm/slub.c:4869 [inline] kmem_cache_alloc_node_noprof+0x25a/0x6f0 mm/slub.c:4921 kmalloc_reserve+0x148/0x350 net/core/skbuff.c:613 __alloc_skb+0x185/0x710 net/core/skbuff.c:713 alloc_skb include/linux/skbuff.h:1383 [inline] synproxy_send_client_synack_ipv6+0x19f/0x7a0 net/netfilter/nf_synproxy_core.c:874 nft_synproxy_eval_v6 net/netfilter/nft_synproxy.c:91 [inline] nft_synproxy_do_eval+0x941/0xd50 net/netfilter/nft_synproxy.c:146 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x2e8/0x1930 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0xee/0x340 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xbf/0x220 net/netfilter/core.c:623 nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:273 NF_HOOK include/linux/netfilter.h:316 [inline] ip6_input+0xe0/0x2f0 net/ipv6/ip6_input.c:500 dst_input include/net/dst.h:480 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ipv6_rcv+0x263/0x3d0 net/ipv6/ip6_input.c:311 __netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:6164 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6277 process_backlog+0x37a/0x1580 net/core/dev.c:6628 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7692 napi_poll net/core/dev.c:7755 [inline] net_rx_action+0xa40/0xf20 net/core/dev.c:7912 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: e8 82 02 c3 cc cc cc cc 0f 1f 00 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 03 f1 1b 00 fb f4 fc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df0 EFLAGS: 00000242 RAX: 00000000044a4f25 RBX: ffff88801e6a24c0 RCX: ffffffff8b8f9c75 RDX: 0000000000000000 RSI: ffffffff8de74cf8 RDI: ffffffff8c1afaa0 RBP: 0000000000000001 R08: 0000000000000001 R09: ffffed10170a6795 R10: ffff8880b8533cab R11: 0000000000000000 R12: ffffed1003cd4498 R13: 0000000000000001 R14: ffffffff90d98310 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:73 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x35b/0x4b0 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x148