rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7120/1:b..l rcu: (detected by 1, t=10502 jiffies, g=12909, q=2078220 ncpus=2) task:syz.0.324 state:R running task stack:25752 pid:7120 tgid:7119 ppid:5820 task_flags:0x40044c flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6947 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:1761 [inline] zap_pmd_range mm/memory.c:1823 [inline] zap_pud_range mm/memory.c:1852 [inline] zap_p4d_range mm/memory.c:1873 [inline] unmap_page_range+0xf08/0x4390 mm/memory.c:1894 unmap_single_vma+0x194/0x2a0 mm/memory.c:1940 unmap_vmas+0x22c/0x490 mm/memory.c:1984 exit_mmap+0x1b9/0xb90 mm/mmap.c:1284 __mmput+0x12a/0x410 kernel/fork.c:1379 mmput+0x62/0x70 kernel/fork.c:1401 exit_mm kernel/exit.c:589 [inline] do_exit+0x9d1/0x2c30 kernel/exit.c:940 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102 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 kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x260 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa89898e969 RSP: 002b:00007fa8967f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: 0000200000000000 RBX: 00007fa898bb5fa0 RCX: 00007fa89898e969 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007fa898a10ab1 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa898bb5fa0 R15: 00007ffeba3ff2b8 rcu: rcu_preempt kthread starved for 549 jiffies! g12909 f0x2 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:27704 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2046 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2248 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 5819 Comm: kworker/1:3 Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: wg-kex-wg0 wg_packet_handshake_receive_worker RIP: 0010:unwind_next_frame+0x78/0x20a0 arch/x86/kernel/unwind_orc.c:470 Code: 41 5f c3 cc cc cc cc 48 b8 00 00 00 00 00 fc ff df 49 8d 6d 48 48 89 ea 48 c1 ea 03 80 3c 02 00 0f 85 5e 18 00 00 49 8b 45 48 <48> 89 44 24 08 49 8d 45 38 48 89 c2 48 89 04 24 48 b8 00 00 00 00 RSP: 0018:ffffc90000a07ff8 EFLAGS: 00000246 RAX: ffffffff89acbd13 RBX: 0000000000000002 RCX: ffffc90000a07fbc RDX: 1ffff92000141016 RSI: ffffffff89acbd13 RDI: ffffc90000a08068 RBP: ffffc90000a080b0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000006 R11: 0000000000089e3b R12: ffffffff81a710c0 R13: ffffc90000a08068 R14: 0000000000000000 R15: ffff888036272440 FS: 0000000000000000(0000) GS:ffff888124ab2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9536107122 CR3: 000000006069a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4161 [inline] slab_alloc_node mm/slub.c:4210 [inline] kmem_cache_alloc_node_noprof+0x1d5/0x3b0 mm/slub.c:4262 __alloc_skb+0x2b2/0x380 net/core/skbuff.c:658 alloc_skb include/linux/skbuff.h:1340 [inline] synproxy_send_client_synack+0x1af/0x8f0 net/netfilter/nf_synproxy_core.c:460 nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:59 [inline] nft_synproxy_do_eval+0xa63/0xd80 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x2e6/0x1920 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:154 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626 nf_hook.constprop.0+0x422/0x750 include/linux/netfilter.h:269 NF_HOOK include/linux/netfilter.h:312 [inline] ip_local_deliver+0x169/0x1f0 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:469 [inline] ip_rcv_finish net/ipv4/ip_input.c:447 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip_rcv+0x2c3/0x5d0 net/ipv4/ip_input.c:567 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5887 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6000 process_backlog+0x442/0x15e0 net/core/dev.c:6352 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7324 napi_poll net/core/dev.c:7388 [inline] net_rx_action+0xa97/0x1010 net/core/dev.c:7510 handle_softirqs+0x216/0x8e0 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:1049 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:virt_to_folio include/linux/mm.h:1402 [inline] RIP: 0010:virt_to_slab mm/slab.h:211 [inline] RIP: 0010:qlink_to_cache mm/kasan/quarantine.c:131 [inline] RIP: 0010:qlist_free_all+0x5e/0x120 mm/kasan/quarantine.c:176 Code: eb ff ff 49 89 c7 66 90 48 89 ee 48 89 df 48 8d 15 00 00 00 00 e8 d2 a7 f5 ff 4d 85 e4 74 75 4c 89 e5 4c 89 eb 4d 85 ed 75 c0 <48> 89 ef e8 7a a7 4a ff 48 b9 00 00 00 00 00 ea ff ff 48 c1 e8 0c RSP: 0018:ffffc90002f178f8 EFLAGS: 00000246 RAX: ffffea0001344640 RBX: 0000000000000000 RCX: 00000000000c000a RDX: 00000000000c000b RSI: ffff88804d119000 RDI: ffffc90002f178c0 RBP: ffff88804fdeba00 R08: 0000000000000001 R09: ffffffff8220dc49 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88804fdeba00 R13: 0000000000000000 R14: ffffc90002f17930 R15: ffff88804d119000 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x8a/0xb0 mm/kasan/common.c:385 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [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+0x17f/0x3a0 drivers/net/wireguard/receive.c:213 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245