rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2632 jiffies s: 78665 root: 0x2/. rcu: blocking rcu_node structures (internal RCU debug): Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8753 Comm: syz.0.1396 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:__this_cpu_preempt_check+0x0/0x10 lib/smp_processor_id.c:65 Code: 48 89 da e8 22 b6 f4 ff 48 8b 74 24 30 48 c7 c7 60 43 df 8a e8 11 b6 f4 ff e8 0a 8c ff ff eb a8 e8 35 ea ff ff 0f 1f 44 00 00 <48> 89 fe 48 c7 c7 e0 42 df 8a e9 e1 fe ff ff 00 eb 1e 0f 1f 00 48 RSP: 0018:ffffc900001dfe18 EFLAGS: 00000082 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8a8c2920 RBP: ffffc900001dff28 R08: dffffc0000000000 R09: 1ffffffff2162048 R10: dffffc0000000000 R11: fffffbfff2162049 R12: 0000000000000001 R13: 1ffff9200003bfd0 R14: 0000000000000046 R15: dffffc0000000000 FS: 00007fcfc8e606c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000017000 CR3: 000000001ca9d000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline] lock_acquire+0x1cb/0x4a0 kernel/locking/lockdep.c:5678 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock_sched include/linux/rcupdate.h:883 [inline] pfn_valid include/linux/mmzone.h:1857 [inline] __virt_addr_valid+0x1a5/0x540 arch/x86/mm/physaddr.c:65 kasan_addr_to_slab+0x9/0xc0 mm/kasan/common.c:36 __kasan_record_aux_stack+0xf/0xc0 mm/kasan/generic.c:471 irq_work_queue_on+0x10f/0x260 kernel/irq_work.c:140 rcu_read_unlock_special+0x3c9/0x510 kernel/rcu/tree_plugin.h:678 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] __perf_event_output kernel/events/core.c:7741 [inline] perf_event_output_forward+0x271/0x2f0 kernel/events/core.c:7750 __perf_event_overflow+0x457/0x630 kernel/events/core.c:9496 perf_swevent_overflow kernel/events/core.c:9579 [inline] perf_swevent_event+0x315/0x570 kernel/events/core.c:9630 perf_tp_event+0x36b/0xc10 kernel/events/core.c:10064 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10032 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728 RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685 Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 52 82 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc900001e0840 EFLAGS: 00000206 RAX: c614962eda45f000 RBX: 1ffff9200003c110 RCX: c614962eda45f000 RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: ffffffff8adf42e0 RBP: ffffc900001e0928 R08: ffffffff90b1030f R09: 1ffffffff2162061 R10: dffffc0000000000 R11: fffffbfff2162062 R12: 0000000000000246 R13: dffffc0000000000 R14: ffff8880b8f3bb00 R15: 0000000000000002 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] arp_xmit+0x20e/0x260 net/ipv4/arp.c:667 arp_solicit+0xbef/0xe10 net/ipv4/arp.c:392 neigh_probe net/core/neighbour.c:1080 [inline] neigh_timer_handler+0xaba/0x1090 net/core/neighbour.c:1162 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x56c/0x810 kernel/time/timer.c:2023 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x291/0x910 kernel/softirq.c:596 __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:__handle_mm_fault mm/memory.c:-1 [inline] RIP: 0010:handle_mm_fault+0x268b/0x3d40 mm/memory.c:5292 Code: 78 0e 00 00 e8 86 02 c2 ff 4c 8b b4 24 48 01 00 00 4d 85 f6 74 0f e8 74 02 c2 ff 4c 89 f7 e8 cc 82 fe ff eb 05 e8 65 02 c2 ff <48> 8b 84 24 88 00 00 00 48 b9 f8 f8 f8 f8 f8 f8 f8 f8 4a 89 4c 28 RSP: 0018:ffffc9000d45f400 EFLAGS: 00000286 RAX: 0000000080000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 00000000ffffffff RBP: ffffc9000d45f5d0 R08: ffff888078e85063 R09: 1ffff1100f1d0a0c R10: dffffc0000000000 R11: ffffed100f1d0a0d R12: ffff888056f43e68 R13: dffffc0000000000 R14: 000000000f90c225 R15: 0000200000017000 do_user_addr_fault+0x58e/0xb20 arch/x86/mm/fault.c:1338 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0010:copy_user_enhanced_fast_string+0xa/0x40 arch/x86/lib/copy_user_64.S:166 Code: ff c9 75 f2 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 8d 0c ca 89 ca eb 20 0f 01 cb 83 fa 40 72 38 89 d1 a4 31 c0 0f 01 ca c3 89 ca eb 0a 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc9000d45f788 EFLAGS: 00050206 RAX: ffffffff84133c01 RBX: 0000000000033fe0 RCX: 000000000001d020 RDX: 0000000000033fe0 RSI: 0000200000017000 RDI: ffffc9000d4f7fc0 RBP: 0000000000000000 R08: ffffc9000d514fdf R09: 1ffff92001aa29fb R10: dffffc0000000000 R11: fffff52001aa29fc R12: 00007ffffffcb020 R13: 0000000000000000 R14: 0000200000000040 R15: ffffc9000d4e1000 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:52 [inline] copyin+0xe7/0x120 lib/iov_iter.c:183 _copy_from_iter+0x447/0x1130 lib/iov_iter.c:632 copy_from_iter include/linux/uio.h:187 [inline] copy_from_iter_full include/linux/uio.h:194 [inline] memcpy_from_msg include/linux/skbuff.h:4076 [inline] netlink_sendmsg+0x755/0xbd0 net/netlink/af_netlink.c:1862 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5ed/0x9a0 net/socket.c:2519 ___sys_sendmsg+0x2a2/0x360 net/socket.c:2573 __sys_sendmsg net/socket.c:2602 [inline] __do_sys_sendmsg net/socket.c:2611 [inline] __se_sys_sendmsg+0x1c3/0x2b0 net/socket.c:2609 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fcfc7f9de99 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fcfc8e60028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fcfc8225fa0 RCX: 00007fcfc7f9de99 RDX: 0000000000000000 RSI: 0000200000000000 RDI: 000000000000000c RBP: 00007fcfc8033eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcfc8226038 R14: 00007fcfc8225fa0 R15: 00007fffece7fda8