rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-....: (4 ticks this GP) idle=1b5/1/0x4000000000000000 softirq=7844/7844 fqs=5245 (detected by 1, t=10502 jiffies, g=9333, q=1543) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4822 Comm: syz.1.153 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:hlock_class kernel/locking/lockdep.c:197 [inline] RIP: 0010:mark_lock+0x9c/0x320 kernel/locking/lockdep.c:4569 Code: 89 c7 41 81 e7 ff 1f 00 00 c1 e8 03 25 f8 03 00 00 48 8d b8 c0 70 1b 90 be 08 00 00 00 e8 ac 69 60 00 4c 0f a3 3d 74 c4 bd 0e <73> 10 4b 8d 04 7f c1 e0 06 4c 8d b8 80 ef b3 8f eb 24 48 c7 c0 80 RSP: 0018:ffffc90000007600 EFLAGS: 00000057 RAX: 0000000000000001 RBX: ffff888025de1dc0 RCX: ffffffff815dac44 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff901b7170 RBP: 0000000000000002 R08: ffffffff901b7177 R09: 1ffffffff2036e2e R10: dffffc0000000000 R11: fffffbfff2036e2f R12: 0000000000000004 R13: dffffc0000000000 R14: ffff888025de2900 R15: 00000000000005a5 FS: 00007f7e5a9a36c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000005f66e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mark_held_locks kernel/locking/lockdep.c:4193 [inline] __trace_hardirqs_on_caller kernel/locking/lockdep.c:4211 [inline] lockdep_hardirqs_on_prepare+0x249/0x770 kernel/locking/lockdep.c:4278 trace_hardirqs_on+0x67/0x80 kernel/trace/trace_preemptirq.c:49 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674 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 12 ff 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc900000077c0 EFLAGS: 00000206 RAX: 59ad0846e77e8d00 RBX: 1ffff92000000efc RCX: 59ad0846e77e8d00 RDX: dffffc0000000000 RSI: ffffffff8a2b1c00 RDI: ffffffff8a79e740 RBP: ffffc900000078a0 R08: ffffffff901b71c7 R09: 1ffffffff2036e38 R10: dffffc0000000000 R11: fffffbfff2036e39 R12: ffffffff8c320c00 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+0xde0/0x1500 net/ipv6/ndisc.c:521 addrconf_rs_timer+0x2d1/0x630 net/ipv6/addrconf.c:3956 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x53a/0x7f0 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x339/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [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 bf bc 8e f7 65 8b 05 40 d9 3e 76 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc900032eef40 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: 59ad0846e77e8d00 RDX: dffffc0000000000 RSI: ffffffff8a2b1c00 RDI: 0000000000000001 RBP: ffffc900032eefd8 R08: ffffffff901b7177 R09: 1ffffffff2036e2e R10: dffffc0000000000 R11: fffffbfff2036e2f R12: dffffc0000000000 R13: ffff888025300000 R14: ffffffff9653c978 R15: 1ffff9200065dde8 __debug_check_no_obj_freed lib/debugobjects.c:982 [inline] debug_check_no_obj_freed+0x515/0x530 lib/debugobjects.c:1003 free_pages_prepare mm/page_alloc.c:1345 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x237/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396 free_slab mm/slub.c:2020 [inline] discard_slab mm/slub.c:2026 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2512 put_cpu_partial+0x12d/0x190 mm/slub.c:2592 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x100/0x290 mm/slub.c:3238 ptlock_alloc+0x1c/0x60 mm/memory.c:5556 ptlock_init include/linux/mm.h:2241 [inline] pgtable_pte_page_ctor include/linux/mm.h:2268 [inline] __pte_alloc_one include/asm-generic/pgalloc.h:66 [inline] pte_alloc_one+0xc0/0x310 arch/x86/mm/pgtable.c:33 __pte_alloc+0x21/0x150 mm/memory.c:439 copy_pte_range mm/memory.c:1032 [inline] copy_pmd_range mm/memory.c:1167 [inline] copy_pud_range mm/memory.c:1204 [inline] copy_p4d_range mm/memory.c:1228 [inline] copy_page_range+0x29c2/0x3230 mm/memory.c:1301 dup_mmap kernel/fork.c:615 [inline] dup_mm kernel/fork.c:1466 [inline] copy_mm+0xc86/0x13f0 kernel/fork.c:1518 copy_process+0x17eb/0x3e20 kernel/fork.c:2290 kernel_clone+0x23f/0x990 kernel/fork.c:2679 __do_sys_clone kernel/fork.c:2796 [inline] __se_sys_clone kernel/fork.c:2780 [inline] __x64_sys_clone+0x19a/0x210 kernel/fork.c:2780 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: 0033:0x7f7e5c747cb9 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:00007f7e5a9a2fd8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f7e5c9c2fa0 RCX: 00007f7e5c747cb9 RDX: 0000000000000000 RSI: 0000000000000700 RDI: 00000000a49a4080 RBP: 00007f7e5c7b5bf7 R08: ffffffffff600000 R09: ffffffffff600000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007f7e5c9c3038 R14: 00007f7e5c9c2fa0 R15: 00007ffd5424bc48