rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9532/1:b..l P7281/1:b..l rcu: (detected by 1, t=10503 jiffies, g=30309, q=295 ncpus=2) task:syz-executor state:R running task stack:23544 pid:7281 tgid:7281 ppid:7262 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7108 irqentry_exit+0x36/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_release+0x183/0x2f0 kernel/locking/lockdep.c:5896 Code: 0f c1 05 48 7a 38 12 83 f8 01 0f 85 1d 01 00 00 9c 58 f6 c4 02 0f 85 08 01 00 00 41 f7 c5 00 02 00 00 74 01 fb 48 8b 44 24 10 <65> 48 2b 05 5d 38 38 12 0f 85 58 01 00 00 48 83 c4 18 5b 41 5c 41 RSP: 0018:ffffc900040a7348 EFLAGS: 00000206 RAX: 5e8023e46ae17300 RBX: ffffffff8e5c4940 RCX: ffffc900040a7354 RDX: 0000000000000001 RSI: ffffffff8de0c233 RDI: ffffffff8c1587e0 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 000000000001180e R12: ffffffff816acad4 R13: 0000000000000206 R14: ffff88802eeb4880 R15: 0000000000000002 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x3f9/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706 discard_slab mm/slub.c:2717 [inline] __put_partials+0x16d/0x1c0 mm/slub.c:3186 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x8a/0xb0 mm/kasan/common.c:385 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4328 [inline] __kmalloc_node_noprof+0x21e/0x500 mm/slub.c:4334 kmalloc_node_noprof include/linux/slab.h:932 [inline] __vmalloc_area_node mm/vmalloc.c:3690 [inline] __vmalloc_node_range_noprof+0x3e5/0x14b0 mm/vmalloc.c:3885 __vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:3948 xt_counters_alloc+0x4c/0x70 net/netfilter/x_tables.c:1380 __do_replace+0x97/0x9e0 net/ipv4/netfilter/ip_tables.c:1046 do_replace net/ipv4/netfilter/ip_tables.c:1141 [inline] do_ipt_set_ctl+0x86d/0xae0 net/ipv4/netfilter/ip_tables.c:1635 nf_setsockopt+0x8a/0xf0 net/netfilter/nf_sockopt.c:101 ip_setsockopt+0xcb/0xf0 net/ipv4/ip_sockglue.c:1424 tcp_setsockopt+0xa7/0x100 net/ipv4/tcp.c:4108 do_sock_setsockopt+0x221/0x470 net/socket.c:2296 __sys_setsockopt+0x1a0/0x230 net/socket.c:2321 __do_sys_setsockopt net/socket.c:2327 [inline] __se_sys_setsockopt net/socket.c:2324 [inline] __x64_sys_setsockopt+0xbd/0x160 net/socket.c:2324 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1371f9081a RSP: 002b:00007ffc6fb9aad8 EFLAGS: 00000206 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007ffc6fb9ab60 RCX: 00007f1371f9081a RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000408 R09: 00007ffc6fb9af17 R10: 00007f1372183c20 R11: 0000000000000206 R12: 00007f1372183bc0 R13: 00007ffc6fb9aafc R14: 0000000000000000 R15: 00007f1372185000 task:syz.9.1020 state:R running task stack:27560 pid:9532 tgid:9529 ppid:7289 task_flags:0x40044c flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6965 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:1765 [inline] zap_pmd_range mm/memory.c:1827 [inline] zap_pud_range mm/memory.c:1856 [inline] zap_p4d_range mm/memory.c:1877 [inline] unmap_page_range+0x106b/0x4350 mm/memory.c:1898 unmap_single_vma.constprop.0+0x153/0x240 mm/memory.c:1941 unmap_vmas+0x218/0x470 mm/memory.c:1985 exit_mmap+0x1b9/0xb90 mm/mmap.c:1284 __mmput+0x12a/0x410 kernel/fork.c:1121 mmput+0x62/0x70 kernel/fork.c:1144 exit_mm kernel/exit.c:581 [inline] do_exit+0x7c4/0x2bd0 kernel/exit.c:952 do_group_exit+0xd3/0x2a0 kernel/exit.c:1105 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f014e38e929 RSP: 002b:00007f014f241038 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffea RBX: 00007f014e5b6160 RCX: 00007f014e38e929 RDX: 0000000000000019 RSI: 0000000000600003 RDI: 0000200000000000 RBP: 00007f014e410b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f014e5b6160 R15: 00007fff6249c878 rcu: rcu_preempt kthread starved for 8734 jiffies! g30309 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27464 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6878 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-rc4-syzkaller-00308-ga79a588fc176 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:check_preemption_disabled+0x27/0xe0 lib/smp_processor_id.c:56 Code: 90 90 90 41 54 55 53 48 83 ec 08 65 8b 1d 35 5c 48 08 65 8b 05 2a 5c 48 08 a9 ff ff ff 7f 74 0f 48 83 c4 08 89 d8 5b 5d 41 5c c4 de 02 00 9c 58 f6 c4 02 74 ea 48 89 fd 65 48 8b 05 ea 5b 48 RSP: 0018:ffffc90000007068 EFLAGS: 00000096 RAX: 0000000000000000 RBX: ffffffff8e5c4940 RCX: ffffc9000000707c RDX: 0000000000000003 RSI: ffffffff8de0c233 RDI: ffffffff8c1587e0 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 000000000008bd38 R12: ffffffff816acad4 R13: 0000000000000206 R14: ffffffff8e297780 R15: 0000000000000004 FS: 0000000000000000(0000) GS:ffff888124715000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc81d0ffc8 CR3: 000000000e382000 CR4: 00000000003526f0 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:473 [inline] lock_release+0x153/0x2f0 kernel/locking/lockdep.c:5894 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x3f9/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kmem_cache_free+0x2d1/0x4d0 mm/slub.c:4745 skb_kfree_head net/core/skbuff.c:1046 [inline] skb_kfree_head net/core/skbuff.c:1043 [inline] skb_free_head+0x1b7/0x210 net/core/skbuff.c:1060 skb_release_data+0x776/0x9c0 net/core/skbuff.c:1087 skb_release_all net/core/skbuff.c:1152 [inline] __kfree_skb net/core/skbuff.c:1166 [inline] consume_skb net/core/skbuff.c:1398 [inline] consume_skb+0xbf/0x100 net/core/skbuff.c:1392 nft_synproxy_eval_v6 net/netfilter/nft_synproxy.c:91 [inline] nft_synproxy_do_eval+0x943/0xd80 net/netfilter/nft_synproxy.c:145 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x2e9/0x1920 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x18a/0x340 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline] nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623 nf_hook.constprop.0+0x422/0x750 include/linux/netfilter.h:272 NF_HOOK include/linux/netfilter.h:315 [inline] ip6_input+0xe0/0x2f0 net/ipv6/ip6_input.c:491 dst_input include/net/dst.h:469 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline] NF_HOOK include/linux/netfilter.h:317 [inline] NF_HOOK include/linux/netfilter.h:311 [inline] ipv6_rcv+0x265/0x680 net/ipv6/ip6_input.c:309 __netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:5977 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6090 process_backlog+0x442/0x15e0 net/core/dev.c:6442 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7414 napi_poll net/core/dev.c:7478 [inline] net_rx_action+0xa9f/0xfe0 net/core/dev.c:7605 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 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+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: cb 6b 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 53 c0 21 00 fb f4 0c fb 02 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e207e08 EFLAGS: 000002c6 RAX: 00000000036f7fad RBX: 0000000000000000 RCX: ffffffff8b884c69 RDX: 0000000000000000 RSI: ffffffff8de31723 RDI: ffffffff8c1587e0 RBP: fffffbfff1c52ef0 R08: 0000000000000001 R09: ffffed1017086645 R10: ffff8880b843322b R11: 0000000000000001 R12: 0000000000000000 R13: ffffffff8e297780 R14: ffffffff90a97550 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:749 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 rest_init+0x16b/0x2b0 init/main.c:745 start_kernel+0x3ee/0x4d0 init/main.c:1102 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x148