rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 ticks this GP) idle=ef1/1/0x4000000000000000 softirq=46450/46450 fqs=0 (detected by 1, t=10502 jiffies, g=67073, q=881) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 15523 Comm: syz.1.2829 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:202 Code: 66 2e 0f 1f 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d d0 6b f1 0b 48 89 de 5b e9 d7 9e 43 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d a4 a3 8a 7e 65 8b 15 a5 a3 8a 7e 81 e2 00 RSP: 0018:ffffc90000006fe0 EFLAGS: 00000002 RAX: ffffffff81839421 RBX: 0000000000000102 RCX: ffff888020528000 RDX: 0000000000000100 RSI: 0000000000000102 RDI: 0000000000000000 RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed10172067af R10: ffffed10172067af R11: 1ffff110172067ae R12: 0000000000000000 R13: dffffc0000000001 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fe4adc2e6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000005f3bb000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: irq_work_queue_on+0x17a/0x220 kernel/irq_work.c:111 rcu_read_unlock_special+0x379/0x480 kernel/rcu/tree_plugin.h:667 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] __perf_event_output kernel/events/core.c:7813 [inline] perf_event_output_forward+0x216/0x280 kernel/events/core.c:7822 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10047 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021 perf_trace_preemptirq_template+0x2be/0x380 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674 Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ed 11 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b RSP: 0018:ffffc900000077a0 EFLAGS: 00000206 RAX: da1aeb15b5eebd00 RBX: 1ffff92000000ef8 RCX: da1aeb15b5eebd00 RDX: dffffc0000000000 RSI: ffffffff8a0b1be0 RDI: ffffffff8a59e800 RBP: ffffc90000007880 R08: dffffc0000000000 R09: fffffbfff1ff5439 R10: fffffbfff1ff5439 R11: 1ffffffff1ff5438 R12: ffffffff8c120c00 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] ndisc_send_skb+0xdc4/0x14a0 net/ipv6/ndisc.c:521 addrconf_rs_timer+0x2b8/0x600 net/ipv6/addrconf.c:3956 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x525/0x7c0 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x328/0x820 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:deref_stack_reg+0x1/0x120 arch/x86/kernel/unwind_orc.c:356 Code: 87 00 e9 98 f7 ff ff 44 89 f1 80 e1 07 38 c1 0f 8c e6 f4 ff ff 4c 89 f7 e8 5c 9e 87 00 e9 d9 f4 ff ff 0f 1f 80 00 00 00 00 55 <41> 57 41 56 41 55 41 54 53 48 89 d3 49 89 f6 49 89 ff 49 bc 00 00 RSP: 0018:ffffc90002e3f058 EFLAGS: 00000287 RAX: fffffffffffffff0 RBX: ffffc90002e3f188 RCX: 0000000000000000 RDX: ffffc90002e3f1c8 RSI: ffffc90002e3f178 RDI: ffffc90002e3f188 RBP: ffffc90002e3f1d0 R08: dffffc0000000000 R09: ffffc90002e3f1d8 R10: fffff520005c7e3d R11: 1ffff920005c7e3b R12: 1ffffffff1bc4fbd R13: dffffc0000000000 R14: ffffc90002e3f1d8 R15: ffffffff8de27de6 unwind_next_frame+0x115d/0x1d90 arch/x86/kernel/unwind_orc.c:-1 __unwind_start+0x5bb/0x740 arch/x86/kernel/unwind_orc.c:704 unwind_start arch/x86/include/asm/unwind.h:60 [inline] arch_stack_walk+0xda/0x140 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 bpf_check+0xa1e5/0xf090 kernel/bpf/verifier.c:14253 bpf_prog_load+0x1043/0x1550 kernel/bpf/syscall.c:2354 __sys_bpf+0x4c2/0x670 kernel/bpf/syscall.c:4657 __do_sys_bpf kernel/bpf/syscall.c:4761 [inline] __se_sys_bpf kernel/bpf/syscall.c:4759 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4759 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe4af9e8749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe4adc2e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fe4afc3f090 RCX: 00007fe4af9e8749 RDX: 0000000000000094 RSI: 00002000000000c0 RDI: 0000000000000005 RBP: 00007fe4afa6cf91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe4afc3f128 R14: 00007fe4afc3f090 R15: 00007ffef57826b8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g67073 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=33998 rcu: rcu_preempt kthread starved for 10502 jiffies! g67073 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27424 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 15523 Comm: syz.1.2829 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:202 Code: 66 2e 0f 1f 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d d0 6b f1 0b 48 89 de 5b e9 d7 9e 43 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d a4 a3 8a 7e 65 8b 15 a5 a3 8a 7e 81 e2 00 RSP: 0018:ffffc90000007038 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffffc900000071e0 RCX: ffff888020528000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000007130 R08: dffffc0000000000 R09: ffffc90000007180 R10: fffff52000000e37 R11: 1ffff92000000e30 R12: dffffc0000000000 R13: ffffc900000071e6 R14: 0000000000000000 R15: ffffc90000007340 FS: 00007fe4adc2e6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000005f3bb000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: perf_prepare_sample+0x6e9/0x1cb0 kernel/events/core.c:7665 __perf_event_output kernel/events/core.c:7802 [inline] perf_event_output_forward+0x146/0x280 kernel/events/core.c:7822 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10047 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021 perf_trace_preemptirq_template+0x2be/0x380 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674 Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ed 11 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b RSP: 0018:ffffc900000077a0 EFLAGS: 00000206 RAX: da1aeb15b5eebd00 RBX: 1ffff92000000ef8 RCX: da1aeb15b5eebd00 RDX: dffffc0000000000 RSI: ffffffff8a0b1be0 RDI: ffffffff8a59e800 RBP: ffffc90000007880 R08: dffffc0000000000 R09: fffffbfff1ff5439 R10: fffffbfff1ff5439 R11: 1ffffffff1ff5438 R12: ffffffff8c120c00 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] ndisc_send_skb+0xdc4/0x14a0 net/ipv6/ndisc.c:521 addrconf_rs_timer+0x2b8/0x600 net/ipv6/addrconf.c:3956 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x525/0x7c0 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x328/0x820 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:deref_stack_reg+0x1/0x120 arch/x86/kernel/unwind_orc.c:356 Code: 87 00 e9 98 f7 ff ff 44 89 f1 80 e1 07 38 c1 0f 8c e6 f4 ff ff 4c 89 f7 e8 5c 9e 87 00 e9 d9 f4 ff ff 0f 1f 80 00 00 00 00 55 <41> 57 41 56 41 55 41 54 53 48 89 d3 49 89 f6 49 89 ff 49 bc 00 00 RSP: 0018:ffffc90002e3f058 EFLAGS: 00000287 RAX: fffffffffffffff0 RBX: ffffc90002e3f188 RCX: 0000000000000000 RDX: ffffc90002e3f1c8 RSI: ffffc90002e3f178 RDI: ffffc90002e3f188 RBP: ffffc90002e3f1d0 R08: dffffc0000000000 R09: ffffc90002e3f1d8 R10: fffff520005c7e3d R11: 1ffff920005c7e3b R12: 1ffffffff1bc4fbd R13: dffffc0000000000 R14: ffffc90002e3f1d8 R15: ffffffff8de27de6 unwind_next_frame+0x115d/0x1d90 arch/x86/kernel/unwind_orc.c:-1 __unwind_start+0x5bb/0x740 arch/x86/kernel/unwind_orc.c:704 unwind_start arch/x86/include/asm/unwind.h:60 [inline] arch_stack_walk+0xda/0x140 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 bpf_check+0xa1e5/0xf090 kernel/bpf/verifier.c:14253 bpf_prog_load+0x1043/0x1550 kernel/bpf/syscall.c:2354 __sys_bpf+0x4c2/0x670 kernel/bpf/syscall.c:4657 __do_sys_bpf kernel/bpf/syscall.c:4761 [inline] __se_sys_bpf kernel/bpf/syscall.c:4759 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4759 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe4af9e8749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe4adc2e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fe4afc3f090 RCX: 00007fe4af9e8749 RDX: 0000000000000094 RSI: 00002000000000c0 RDI: 0000000000000005 RBP: 00007fe4afa6cf91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe4afc3f128 R14: 00007fe4afc3f090 R15: 00007ffef57826b8