rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P25922/1:b..l rcu: (detected by 1, t=10503 jiffies, g=263597, q=1776 ncpus=2) task:syz.3.14016 state:R running task stack:23448 pid:25922 tgid:25921 ppid:19006 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7234 irqentry_exit+0x599/0x620 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:141 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:172 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:191 [inline] RIP: 0010:kasan_check_range+0x5d/0x2c0 mm/kasan/generic.c:200 Code: cc cc 49 b9 00 00 00 00 00 00 00 ff 4c 39 cf 0f 82 14 02 00 00 49 89 ff 49 c1 ef 03 49 ba 00 00 00 00 00 fc ff df 4f 8d 1c 17 <49> ff c8 4d 89 c1 49 c1 e9 03 48 bb 01 00 00 00 00 fc ff df 4d 8d RSP: 0018:ffffc90006f0f340 EFLAGS: 00000a02 RAX: ffffc90006f0fd01 RBX: 0000000000000010 RCX: ffffffff8176884e RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc90006f0f4b8 RBP: 0000000000000000 R08: ffffc90006f0f4c8 R09: ffff800000000000 R10: dffffc0000000000 R11: fffff52000de1e97 R12: ffffc90006f0f4b8 R13: 1ffff92000de1e8f R14: ffffc90006f0f4b8 R15: 1ffff92000de1e97 __asan_memset+0x22/0x50 mm/kasan/shadow.c:84 unwind_next_frame+0xeae/0x23c0 arch/x86/kernel/unwind_orc.c:607 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 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+0xc2b/0xdb0 mm/page_alloc.c:2978 __slab_free+0x263/0x2b0 mm/slub.c:5532 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4501 [inline] slab_alloc_node mm/slub.c:4830 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4837 alloc_empty_file+0x55/0x1d0 fs/file_table.c:237 path_openat+0x10f/0x3860 fs/namei.c:4816 do_file_open+0x23e/0x4a0 fs/namei.c:4859 do_sys_openat2+0x113/0x200 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+0x138/0x170 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc84535cfce RSP: 002b:00007fc8435f5f18 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fc8435f66c0 RCX: 00007fc84535cfce RDX: 0000000000000000 RSI: 00007fc845432270 RDI: ffffffffffffff9c RBP: 00007fc845432bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc845616038 R14: 00007fc845615fa0 R15: 00007ffe95fe5f58 rcu: rcu_preempt kthread starved for 3065 jiffies! g263597 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:27664 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 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: CPU: 1 UID: 0 PID: 4321 Comm: kworker/u8:21 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: wg-kex-wg2 wg_packet_handshake_send_worker RIP: 0010:in_irqentry_text kernel/stacktrace.c:381 [inline] RIP: 0010:filter_irq_stacks+0x5c/0xa0 kernel/stacktrace.c:397 Code: 74 08 4c 89 ff e8 b4 f3 7e 00 49 8b 04 de 48 3d 30 02 00 81 0f 93 c1 48 3d 90 16 00 81 0f 92 c2 84 d1 75 27 48 3d e0 3c b0 8b <0f> 92 c1 48 3d fb 3c b0 8b 0f 93 c0 08 c8 74 11 48 ff c3 49 83 c7 RSP: 0018:ffffc90000a07888 EFLAGS: 00000283 RAX: ffffffff897c964e RBX: 0000000000000007 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000020 RDI: ffffc90000a07910 RBP: ffffc90000a07b40 R08: 000000000000001e R09: ffffffff8e7602e0 R10: ffffc90000a07818 R11: ffffffff81b0b100 R12: 0000000000000020 R13: dffffc0000000000 R14: ffffc90000a07910 R15: ffffc90000a07948 FS: 0000000000000000(0000) GS:ffff888125564000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0cea9dcd58 CR3: 0000000034d6a000 CR4: 00000000003526f0 Call Trace: stack_depot_save_flags+0x33/0x810 lib/stackdepot.c:667 kasan_save_stack mm/kasan/common.c:58 [inline] kasan_save_track+0x4f/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2687 [inline] slab_free mm/slub.c:6124 [inline] kmem_cache_free+0x187/0x630 mm/slub.c:6254 consume_skb net/core/skbuff.c:1450 [inline] skb_pp_cow_data+0xfdb/0x1680 net/core/skbuff.c:1011 netif_skb_check_for_xdp net/core/dev.c:5515 [inline] netif_receive_generic_xdp net/core/dev.c:5556 [inline] do_xdp_generic+0x76b/0x12e0 net/core/dev.c:5624 __netif_receive_skb_core+0x10e5/0x31a0 net/core/dev.c:5977 __netif_receive_skb_one_core net/core/dev.c:6165 [inline] __netif_receive_skb net/core/dev.c:6280 [inline] netif_receive_skb_internal net/core/dev.c:6366 [inline] netif_receive_skb+0x1fe/0xc50 net/core/dev.c:6425 NF_HOOK+0xa4/0x3a0 include/linux/netfilter.h:319 br_handle_frame_finish+0x14b2/0x1b40 net/bridge/br_input.c:-1 br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0xa3a/0xd70 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x374/0x6f0 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0x1277/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core+0x98f/0x31a0 net/core/dev.c:6054 __netif_receive_skb_one_core net/core/dev.c:6165 [inline] __netif_receive_skb net/core/dev.c:6280 [inline] process_backlog+0x76d/0x1950 net/core/dev.c:6631 __napi_poll+0xae/0x340 net/core/dev.c:7695 napi_poll net/core/dev.c:7758 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7910 handle_softirqs+0x22a/0x870 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 blake2s_compress+0xf9/0x1eb0 lib/crypto/x86/blake2s.h:42 blake2s_update+0x14b/0x450 lib/crypto/blake2s.c:119 hmac+0x2d3/0x3b0 drivers/net/wireguard/noise.c:332 kdf+0xff/0x2b0 drivers/net/wireguard/noise.c:360 mix_dh drivers/net/wireguard/noise.c:413 [inline] wg_noise_handshake_create_initiation+0x2bc/0x830 drivers/net/wireguard/noise.c:550 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline] wg_packet_handshake_send_worker+0x18d/0x350 drivers/net/wireguard/send.c:51 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245