rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6844/1:b..l rcu: (detected by 0, t=10503 jiffies, g=330177, q=2374 ncpus=2) task:syz.7.7564 state:R running task stack:28760 pid:6844 tgid:6836 ppid:17939 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x760 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__preempt_count_add arch/x86/include/asm/preempt.h:80 [inline] RIP: 0010:rcu_is_watching+0x9/0xb0 kernel/rcu/tree.c:751 Code: 44 03 eb cc 66 66 66 66 2e 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 41 57 41 56 53 <65> ff 05 10 c2 8e 11 e8 7b b2 fe 09 89 c3 83 f8 08 73 65 49 bf 00 RSP: 0018:ffffc90004e6f6e8 EFLAGS: 00000297 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000080000 RDX: ffffc900140b3000 RSI: ffffffff81d5ab56 RDI: ffffffff8e95cce0 RBP: 0000000000000000 R08: ffffffff81d5ab56 R09: ffffffff8e95cce0 R10: ffffc90004e6f858 R11: ffffffff81b0e030 R12: 0000000000000004 R13: ffffffff81d5ab56 R14: ffffffff8e95cce0 R15: 0000000000000000 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x4b/0x3c0 kernel/locking/lockdep.c:5879 rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:869 [inline] is_bpf_text_address+0x28d/0x2b0 kernel/bpf/core.c:749 kernel_text_address+0xa5/0xe0 kernel/extable.c:125 __kernel_text_address+0xd/0x30 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385 arch_stack_walk+0xfb/0x150 arch/x86/kernel/stacktrace.c:26 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:1397 [inline] __free_frozen_pages+0xc1c/0xd30 mm/page_alloc.c:2938 __slab_free+0x274/0x2c0 mm/slub.c:5613 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x22/0xb0 mm/kasan/common.c:406 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5296 [inline] __kmalloc_noprof+0x35c/0x760 mm/slub.c:5308 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] lsm_blob_alloc security/security.c:218 [inline] lsm_sock_alloc security/security.c:4478 [inline] security_sk_alloc+0x52/0x360 security/security.c:4494 sk_prot_alloc+0x101/0x210 net/core/sock.c:2250 sk_alloc+0x3a/0x390 net/core/sock.c:2303 inet_create+0x7a0/0x1000 net/ipv4/af_inet.c:333 __sock_create+0x4b2/0x9d0 net/socket.c:1664 sock_create net/socket.c:1722 [inline] __sys_socket_create net/socket.c:1759 [inline] __sys_socket+0xd6/0x1b0 net/socket.c:1806 __do_sys_socket net/socket.c:1820 [inline] __se_sys_socket net/socket.c:1818 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1818 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9dec59ce59 RSP: 002b:00007f9ded420028 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 00007f9dec816270 RCX: 00007f9dec59ce59 RDX: 0000000000000084 RSI: 0000000000000005 RDI: 0000000000000002 RBP: 00007f9dec632d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9dec816308 R14: 00007f9dec816270 R15: 00007f9dec93fa48 rcu: rcu_preempt kthread starved for 1952 jiffies! g330177 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:27536 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 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+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 31535 Comm: kworker/u8:26 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:kasan_check_range+0x1ce/0x2c0 mm/kasan/generic.c:200 Code: 49 8d 5c 24 07 4d 85 e4 49 0f 49 dc 48 83 e3 f8 49 29 dc 74 0e 41 80 3b 00 75 7c 49 ff c3 49 ff cc 75 f2 5b 41 5c 41 5d 41 5e <41> 5f 5d e9 8a 75 7b 09 cc 45 84 ff 0f 85 a1 00 00 00 41 f7 c7 00 RSP: 0018:ffffc90000a08bb8 EFLAGS: 00000256 RAX: 1ffff11030e10e01 RBX: 0000000000000010 RCX: ffffffff89814dd3 RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffff888187087500 RBP: 0000000000000000 R08: ffff88818708750f R09: 1ffff11030e10ea1 R10: dffffc0000000000 R11: ffffed1030e10ea2 R12: ffff8880b873c998 R13: ffff888187087500 R14: ffff888187087500 R15: 1ffff11030e10ea0 FS: 0000000000000000(0000) GS:ffff888125387000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000153030 CR3: 000000000e74a000 CR4: 00000000003526f0 DR0: 0000000000000101 DR1: 0000000000000007 DR2: 000000000000000f DR3: 0000000000000006 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: __asan_memset+0x22/0x50 mm/kasan/shadow.c:84 __skb_unlink include/linux/skbuff.h:2486 [inline] __skb_dequeue include/linux/skbuff.h:2503 [inline] process_backlog+0x553/0x1950 net/core/dev.c:6663 __napi_poll+0xae/0x340 net/core/dev.c:7733 napi_poll net/core/dev.c:7796 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7953 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xfcf/0x13d0 kernel/smp.c:892 Code: 79 45 8b 2e 44 89 ee 83 e6 01 31 ff e8 9a 07 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 45 03 0c 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 2a 03 0c RSP: 0018:ffffc90004f2f700 EFLAGS: 00000293 RAX: ffffffff81b9b2c6 RBX: ffff8880b873c148 RCX: ffff888076301ec0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90004f2f840 R08: ffffffff9030daf7 R09: 1ffffffff2061b5e R10: dffffc0000000000 R11: fffffbfff2061b5f R12: 1ffff110170c8589 R13: dffffc0000000000 R14: ffff8880b8642c48 R15: 0000000000000000 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057 on_each_cpu include/linux/smp.h:72 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline] smp_text_poke_batch_finish+0x5f5/0x1160 arch/x86/kernel/alternative.c:2983 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:906 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245