rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { P19733 1-.... } 2641 jiffies s: 103109 root: 0x2/T rcu: blocking rcu_node structures (internal RCU debug): Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 19747 Comm: syz.0.4684 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:strlen+0x25/0x60 lib/string.c:502 Code: da 0f 1f 40 00 41 57 41 56 41 54 53 48 c7 c0 ff ff ff ff 49 be 00 00 00 00 00 fc ff df 48 89 fb 49 89 c7 48 89 d8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 75 11 48 ff c3 49 8d 47 01 42 80 7c 3f 01 00 RSP: 0018:ffffc900001e0138 EFLAGS: 00000802 RAX: 1ffffffff151a62c RBX: ffffffff8a8d3163 RCX: dffffc0000000000 RDX: ffffffff818c312f RSI: ffffffff8cb2dde0 RDI: ffffffff8a8d3160 RBP: ffffc900001e0250 R08: ffffffff8e200c2f R09: 1ffffffff1c40185 R10: dffffc0000000000 R11: fffffbfff1c40186 R12: dffffc0000000000 R13: 1ffff9200003c034 R14: dffffc0000000000 R15: 0000000000000002 FS: 00007fd6fddf66c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd6ffbea540 CR3: 000000002807c000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000008d24 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __fortify_strlen include/linux/fortify-string.h:196 [inline] trace_event_get_offsets_lock include/trace/events/lock.h:50 [inline] perf_trace_lock+0xd1/0x390 include/trace/events/lock.h:50 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x8ad/0x920 kernel/locking/lockdep.c:5673 rcu_lock_release include/linux/rcupdate.h:355 [inline] rcu_read_unlock include/linux/rcupdate.h:824 [inline] trace_call_bpf+0x5ca/0x6b0 kernel/trace/bpf_trace.c:137 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10027 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 82 22 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:ffffc900001e06a0 EFLAGS: 00000206 RAX: 4fa0007b074fe500 RBX: 1ffff9200003c0dc RCX: 4fa0007b074fe500 RDX: dffffc0000000000 RSI: ffffffff8a8c19a0 RDI: ffffffff8adf1b60 RBP: ffffc900001e07a0 R08: ffffffff90afd357 R09: 1ffffffff215fa6a R10: dffffc0000000000 R11: fffffbfff215fa6b R12: 0000000000000246 R13: dffffc0000000000 R14: ffff8880b8f3b900 R15: 0000000000000002 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] ndisc_send_skb+0xd9d/0x14e0 net/ipv6/ndisc.c:521 ndisc_send_ns net/ipv6/ndisc.c:671 [inline] ndisc_solicit+0x36b/0x660 net/ipv6/ndisc.c:763 neigh_probe net/core/neighbour.c:1080 [inline] neigh_timer_handler+0xaaa/0x1080 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+0x53e/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x2a1/0x930 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194 Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 3f 4e 20 f7 65 8b 05 40 c0 c9 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc90005d37a20 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: 4fa0007b074fe500 RDX: dffffc0000000000 RSI: ffffffff8a8c19a0 RDI: 0000000000000001 RBP: ffffc90005d37aa8 R08: ffff8880b8f3580b R09: 1ffff110171e6b01 R10: dffffc0000000000 R11: ffffed10171e6b02 R12: dffffc0000000000 R13: ffff888025dd6000 R14: ffffffff96e68b18 R15: 1ffff92000ba6f44 __debug_check_no_obj_freed lib/debugobjects.c:988 [inline] debug_check_no_obj_freed+0x515/0x530 lib/debugobjects.c:1009 free_pages_prepare mm/page_alloc.c:1492 [inline] free_pcp_prepare mm/page_alloc.c:1536 [inline] free_unref_page_prepare+0x2a6/0x9a0 mm/page_alloc.c:3413 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3508 free_slab mm/slub.c:2036 [inline] discard_slab mm/slub.c:2042 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2591 put_cpu_partial+0x17c/0x250 mm/slub.c:2667 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc_lru+0x11a/0x2e0 mm/slub.c:3390 alloc_inode_sb include/linux/fs.h:3245 [inline] sock_alloc_inode+0x24/0xc0 net/socket.c:306 alloc_inode fs/inode.c:261 [inline] new_inode_pseudo+0x5f/0x1c0 fs/inode.c:1063 sock_alloc net/socket.c:631 [inline] __sock_create+0x129/0x940 net/socket.c:1513 sock_create net/socket.c:1605 [inline] __sys_socket_create net/socket.c:1642 [inline] __sys_socket+0xc4/0x190 net/socket.c:1670 __do_sys_socket net/socket.c:1683 [inline] __se_sys_socket net/socket.c:1681 [inline] __x64_sys_socket+0x76/0x80 net/socket.c:1681 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: 0033:0x7fd6ffb9ce59 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:00007fd6fddf6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 00007fd6ffe15fa0 RCX: 00007fd6ffb9ce59 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 000000000000001e RBP: 00007fd6ffc32d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd6ffe16038 R14: 00007fd6ffe15fa0 R15: 00007ffec0eeb438