rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=0f1c/1/0x4000000000000000 softirq=22017/22018 fqs=24 rcu: (t=10501 jiffies g=18289 q=1287 ncpus=2) rcu: rcu_preempt kthread starved for 5988 jiffies! g18289 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:27408 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 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: 6794 Comm: syz.2.19 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:__rcu_read_unlock+0x69/0xd0 kernel/rcu/tree_plugin.h:433 Code: 00 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 38 84 c0 75 5f 41 83 3e 00 75 20 43 0f b6 04 3c 84 c0 75 3a 8b 03 3d 00 00 00 40 73 0a <5b> 41 5c 41 5d 41 5e 41 5f c3 0f 0b eb f2 e8 54 00 00 00 eb d9 89 RSP: 0018:ffffc90000006c30 EFLAGS: 00000083 RAX: 0000000000000002 RBX: ffff888018f55e3c RCX: ffff888018f55a00 RDX: 0000000000000100 RSI: ffffffff8afc6f20 RDI: ffff888018f55a00 RBP: ffffc90000006d68 R08: ffffffff8e4a8e2f R09: 1ffffffff1c951c5 R10: dffffc0000000000 R11: fffffbfff1c951c6 R12: 1ffff110031eabc7 R13: ffffc90000006ca0 R14: ffff88801c67db68 R15: dffffc0000000000 FS: 00007f70943c76c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055ecd54d8950 CR3: 000000005f610000 CR4: 00000000003506f0 Call Trace: rcu_read_unlock include/linux/rcupdate.h:818 [inline] __perf_event_output kernel/events/core.c:7984 [inline] perf_event_output_forward+0x2e6/0x3a0 kernel/events/core.c:7993 __perf_event_overflow+0x447/0x630 kernel/events/core.c:9718 perf_swevent_overflow kernel/events/core.c:9794 [inline] perf_swevent_event+0x2f5/0x5c0 kernel/events/core.c:-1 perf_tp_event+0x4f9/0x13a0 kernel/events/core.c:10344 perf_trace_run_bpf_submit+0xf4/0x1c0 kernel/events/core.c:10268 perf_trace_preemptirq_template+0x281/0x340 include/trace/events/preemptirq.h:14 trace_irq_enable+0xbf/0xe0 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x18/0x40 kernel/trace/trace_preemptirq.c:56 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:should_resched arch/x86/include/asm/preempt.h:104 [inline] RIP: 0010:__local_bh_enable_ip+0x136/0x1c0 kernel/softirq.c:413 Code: 8a e8 9e b0 1d 09 65 66 8b 05 86 12 b2 7e 66 85 c0 75 54 bf 01 00 00 00 e8 67 db 09 00 e8 22 60 3a 00 fb 65 8b 05 52 12 b2 7e <85> c0 75 05 e8 31 f8 ae ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00 RSP: 0018:ffffc90000007340 EFLAGS: 00000286 RAX: 0000000000000101 RBX: 0000000000000200 RCX: f6d991782eb5a700 RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6f40 RBP: ffffc900000073d0 R08: ffffffff90da95ff R09: 1ffffffff21b52bf R10: dffffc0000000000 R11: fffffbfff21b52c0 R12: ffffffff893fefd5 R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff92000000e68 local_bh_enable include/linux/bottom_half.h:33 [inline] ip6t_do_table+0x1344/0x1500 net/ipv6/netfilter/ip6_tables.c:375 ip6table_mangle_hook+0x298/0x6e0 net/ipv6/netfilter/ip6table_mangle.c:72 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline] nf_hook_slow+0xbd/0x200 net/netfilter/core.c:626 nf_hook+0x215/0x370 include/linux/netfilter.h:259 NF_HOOK_COND include/linux/netfilter.h:292 [inline] ip6_output+0x272/0x3b0 net/ipv6/ip6_output.c:240 dst_output include/net/dst.h:467 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] ndisc_send_skb+0xbed/0x14b0 net/ipv6/ndisc.c:513 addrconf_rs_timer+0x2bc/0x600 net/ipv6/addrconf.c:4006 call_timer_fn+0x16e/0x530 kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1751 [inline] __run_timers+0x52d/0x7d0 kernel/time/timer.c:2022 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:__schedule+0x14da/0x44d0 kernel/sched/core.c:6705 Code: d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 6c be 65 f7 4c 89 33 4c 89 ef 4c 89 f6 e8 6e f9 88 f6 48 89 c7 e8 96 0b e5 f6 <48> c7 84 24 e0 00 00 00 0e 36 e0 45 48 8b 84 24 b8 00 00 00 4a c7 RSP: 0018:ffffc90003c579a0 EFLAGS: 00000282 RAX: 0000000000000000 RBX: ffff8880b8e3c010 RCX: f6d991782eb5a700 RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: ffff888018f56ff8 RBP: ffffc90003c57b90 R08: ffffffff90da961f R09: 1ffffffff21b52c3 R10: dffffc0000000000 R11: fffffbfff21b52c4 R12: dffffc0000000000 R13: ffff888018f55a00 R14: ffff88802cb10000 R15: ffff888018f55f40 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866 preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xfa/0x110 kernel/locking/spinlock.c:194 __do_sys_perf_event_open kernel/events/core.c:12916 [inline] __se_sys_perf_event_open+0x1802/0x1c20 kernel/events/core.c:12567 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f709358f749 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:00007f70943c7038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007f70937e5fa0 RCX: 00007f709358f749 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000140 RBP: 00007f7093613f91 R08: 0000000000000002 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f70937e6038 R14: 00007f70937e5fa0 R15: 00007ffd925449a8 CPU: 1 PID: 6762 Comm: syz.3.21 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:rcu_read_unlock_special+0x88/0x460 kernel/rcu/tree_plugin.h:698 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 69 3f 93 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:ffffc900001f03a0 EFLAGS: 00000206 RAX: 0d42a0128f932d00 RBX: 1ffff9200003e078 RCX: 0d42a0128f932d00 RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6f40 RBP: ffffc900001f0468 R08: ffffffff90da95ff R09: 1ffffffff21b52bf R10: dffffc0000000000 R11: fffffbfff21b52c0 R12: ffffffff8cd35100 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000002 FS: 00007f45f58b16c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f70937b6000 CR3: 000000007a25a000 CR4: 00000000003506e0 Call Trace: __rcu_read_unlock+0x7c/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:818 [inline] is_bpf_text_address+0x27e/0x2a0 kernel/bpf/core.c:743 kernel_text_address+0xa0/0xd0 kernel/extable.c:125 __kernel_text_address+0xd/0x30 kernel/extable.c:79 unwind_get_return_address+0x5d/0xc0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0x11d/0x190 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] kmem_cache_alloc_node+0x150/0x330 mm/slub.c:3540 kmalloc_reserve+0x95/0x240 net/core/skbuff.c:562 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653 alloc_skb include/linux/skbuff.h:1284 [inline] ndisc_alloc_skb+0xa6/0x450 net/ipv6/ndisc.c:423 ndisc_send_rs+0x2a6/0x610 net/ipv6/ndisc.c:707 addrconf_rs_timer+0x2bc/0x600 net/ipv6/addrconf.c:4006 call_timer_fn+0x16e/0x530 kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1751 [inline] __run_timers+0x52d/0x7d0 kernel/time/timer.c:2022 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:wake_q_add+0x4/0xd0 kernel/sched/core.c:986 Code: 8c 4c 89 fe e8 fd 80 f6 02 e9 58 ff ff ff 89 f9 80 e1 07 80 c1 03 38 c1 7c 90 e8 07 7c 81 00 eb 89 0f 1f 44 00 00 66 0f 1f 00 <41> 57 41 56 41 55 41 54 53 48 89 f3 49 89 fe 4c 8d be 40 0a 00 00 RSP: 0018:ffffc90003b07c38 EFLAGS: 00000283 RAX: ffff88814c722890 RBX: ffffc90003b07cc0 RCX: ffffffff96eb0403 RDX: 0000000000000001 RSI: ffff88802ac55a00 RDI: ffffc90003b07ca0 RBP: ffffc90003b07d30 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000760f78 R12: 1ffff92000760f8c R13: ffff88802ac55a00 R14: ffff88814c722840 R15: ffffc90003a47ac0 __mutex_unlock_slowpath+0x3de/0x6a0 kernel/locking/mutex.c:943 __do_sys_perf_event_open kernel/events/core.c:12918 [inline] __se_sys_perf_event_open+0x180c/0x1c20 kernel/events/core.c:12567 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f45f498f749 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:00007f45f58b1038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007f45f4be5fa0 RCX: 00007f45f498f749 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000140 RBP: 00007f45f4a13f91 R08: 0000000000000002 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f45f4be6038 R14: 00007f45f4be5fa0 R15: 00007ffc76ee6488