rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4673/2:b..l P5359/1:b..l rcu: (detected by 1, t=10502 jiffies, g=28637, q=524 ncpus=2) task:syz-executor state:R running task stack:20992 pid:5359 tgid:5359 ppid:5350 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5264 [inline] __schedule+0x1893/0x4b50 kernel/sched/core.c:6607 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6786 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6810 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 unwind_next_frame+0x18f8/0x22d0 arch/x86/kernel/unwind_orc.c:672 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x430 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1101 [inline] free_unref_page+0xd22/0xea0 mm/page_alloc.c:2619 discard_slab mm/slub.c:2678 [inline] __put_partials+0xeb/0x130 mm/slub.c:3146 put_cpu_partial+0x17c/0x250 mm/slub.c:3221 __slab_free+0x2ea/0x3d0 mm/slub.c:4450 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_lru_noprof+0x139/0x2b0 mm/slub.c:4154 proc_alloc_inode+0x2a/0xc0 fs/proc/inode.c:57 alloc_inode fs/inode.c:263 [inline] new_inode_pseudo fs/inode.c:1110 [inline] new_inode+0x6e/0x310 fs/inode.c:1129 proc_get_inode+0x22/0x660 fs/proc/inode.c:646 proc_lookup_de+0x24e/0x300 fs/proc/generic.c:253 lookup_one_qstr_excl+0x11f/0x260 fs/namei.c:1633 do_unlinkat+0x297/0x830 fs/namei.c:4521 __do_sys_unlink fs/namei.c:4581 [inline] __se_sys_unlink fs/namei.c:4579 [inline] __x64_sys_unlink+0x47/0x50 fs/namei.c:4579 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efeb157d4a7 RSP: 002b:00007efeb185dbd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007efeb157d4a7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007efeb185dc90 RBP: 00007efeb185dc90 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 00007efeb185ed80 R13: 00007efeb15f0a14 R14: 0000555579bb64a8 R15: 0000000000000006 task:klogd state:R running task stack:23680 pid:4673 tgid:4673 ppid:1 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5264 [inline] __schedule+0x1893/0x4b50 kernel/sched/core.c:6607 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6929 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5826 Code: 2b 00 74 08 4c 89 f7 e8 fa 22 8c 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc900033ef380 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff9200067de7c RCX: 81af59a314146300 RDX: dffffc0000000000 RSI: ffffffff8c0ae940 RDI: ffffffff8c60e0c0 RBP: ffffc900033ef4d0 R08: ffffffff9424f787 R09: 1ffffffff2849ef0 R10: dffffc0000000000 R11: fffffbfff2849ef1 R12: 1ffff9200067de78 R13: dffffc0000000000 R14: ffffc900033ef3e0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] is_bpf_text_address+0x46/0x2a0 kernel/bpf/core.c:767 kernel_text_address+0xa7/0xe0 kernel/extable.c:125 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xfd/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x430 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1101 [inline] free_unref_page+0xd22/0xea0 mm/page_alloc.c:2619 __slab_free+0x31b/0x3d0 mm/slub.c:4491 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] __kmalloc_cache_noprof+0x132/0x2c0 mm/slub.c:4291 kmalloc_noprof include/linux/slab.h:878 [inline] syslog_print+0x121/0x9c0 kernel/printk/printk.c:1588 do_syslog+0x3bb/0x810 kernel/printk/printk.c:1766 __do_sys_syslog kernel/printk/printk.c:1858 [inline] __se_sys_syslog kernel/printk/printk.c:1856 [inline] __x64_sys_syslog+0x7c/0x90 kernel/printk/printk.c:1856 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f56c7b33fa7 RSP: 002b:00007ffec9636b98 EFLAGS: 00000206 ORIG_RAX: 0000000000000067 RAX: ffffffffffffffda RBX: 00007f56c7cd24a0 RCX: 00007f56c7b33fa7 RDX: 00000000000003ff RSI: 00007f56c7cd24a0 RDI: 0000000000000002 RBP: 0000000000000000 R08: 0000000000000007 R09: d6281c7a7eb71bd0 R10: 0000000000004000 R11: 0000000000000206 R12: 00007f56c7cd24a0 R13: 00007f56c7cc2212 R14: 00007f56c7cd2530 R15: 00007f56c7cd2530 rcu: rcu_preempt kthread starved for 308 jiffies! g28637 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:25816 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5264 [inline] __schedule+0x1893/0x4b50 kernel/sched/core.c:6607 __schedule_loop kernel/sched/core.c:6684 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6699 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 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: 5285 Comm: kworker/0:8 Not tainted 6.11.0-syzkaller-07462-g1868f9d0260e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Workqueue: wg-kex-wg2 wg_packet_handshake_receive_worker RIP: 0010:__rcu_read_lock+0x5/0xb0 kernel/rcu/tree_plugin.h:412 Code: fc ff ff e9 62 fc ff ff e8 08 a1 43 0a 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 <41> 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 4c 8b 3c 25 c0 d6 RSP: 0018:ffffc90000006740 EFLAGS: 00000082 RAX: 1ffffffff1c61d4a RBX: ffffffff8e30ea50 RCX: ffff88805f39bc00 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000008 RBP: ffff8880b8840040 R08: ffffffff898cc156 R09: fffff52000000cc4 R10: dffffc0000000000 R11: fffff52000000cc4 R12: ffff8882094198c0 R13: 1ffff1104128331a R14: ffff8882094198d0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555579bd9608 CR3: 000000000e734000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock include/linux/rcupdate.h:847 [inline] skb_flow_limit net/core/dev.c:4821 [inline] enqueue_to_backlog+0x296/0xc80 net/core/dev.c:4872 netif_rx_internal+0x17a/0x630 net/core/dev.c:5191 __netif_rx+0x78/0xc0 net/core/dev.c:5211 loopback_xmit+0x454/0x6b0 drivers/net/loopback.c:89 __netdev_start_xmit include/linux/netdevice.h:4916 [inline] netdev_start_xmit include/linux/netdevice.h:4925 [inline] xmit_one net/core/dev.c:3588 [inline] dev_hard_start_xmit+0x27a/0x7e0 net/core/dev.c:3604 sch_direct_xmit+0x29c/0x5d0 net/sched/sch_generic.c:343 qdisc_restart net/sched/sch_generic.c:408 [inline] __qdisc_run+0xbfe/0x2170 net/sched/sch_generic.c:416 __dev_xmit_skb net/core/dev.c:3886 [inline] __dev_queue_xmit+0x111a/0x3e80 net/core/dev.c:4390 dev_queue_xmit include/linux/netdevice.h:3094 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:236 synproxy_send_client_synack+0x8b8/0xf30 net/netfilter/nf_synproxy_core.c:484 nft_synproxy_eval_v4+0x3ca/0x610 net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x362/0xa60 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288 nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5662 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6107 __napi_poll+0xcb/0x490 net/core/dev.c:6771 napi_poll net/core/dev.c:6840 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6962 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:919 [inline] wg_index_hashtable_lookup+0x3c4/0x440 drivers/net/wireguard/peerlookup.c:224 wg_noise_handshake_consume_response+0x269/0x1080 drivers/net/wireguard/noise.c:747 wg_receive_handshake_packet drivers/net/wireguard/receive.c:166 [inline] wg_packet_handshake_receive_worker+0x5f4/0xf50 drivers/net/wireguard/receive.c:213 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244