rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2670 jiffies s: 181317 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: 27799 Comm: syz.4.7240 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__preempt_count_add kernel/rcu/tree.c:717 [inline] RIP: 0010:rcu_is_watching+0x2/0xa0 kernel/rcu/tree.c:720 Code: 8a e8 62 55 c1 08 48 c7 c7 a0 40 b3 8c 4c 89 f6 e8 83 9e cc 02 e9 44 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 41 57 <41> 56 53 65 ff 05 6c ff 95 7e e8 df 69 c1 08 89 c3 83 f8 08 73 60 RSP: 0018:ffffc900001dff60 EFLAGS: 00000002 RAX: ffffffff81a90966 RBX: 0000000000000001 RCX: 0000000000010100 RDX: ffff88807cd73b80 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900001e00b0 R08: ffffc900001e0037 R09: ffffc900001e0020 R10: dffffc0000000000 R11: fffff5200003c007 R12: 1ffff9200003c000 R13: ffffc900001e0100 R14: dffffc0000000000 R15: ffff88806387bc00 FS: 00007f5bbd8ad6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5bbd88cd58 CR3: 00000000351bc000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: rcu_read_unlock+0x1f/0xa0 include/linux/rcupdate.h:820 __perf_output_begin kernel/events/ring_buffer.c:263 [inline] perf_output_begin_forward+0x7ea/0xa80 kernel/events/ring_buffer.c:272 __perf_event_output kernel/events/core.c:7732 [inline] perf_event_output_forward+0x1ad/0x2f0 kernel/events/core.c:7750 __perf_event_overflow+0x448/0x610 kernel/events/core.c:9496 perf_event_overflow kernel/events/core.c:9517 [inline] perf_swevent_hrtimer+0x472/0x630 kernel/events/core.c:10967 __run_hrtimer kernel/time/hrtimer.c:1747 [inline] __hrtimer_run_queues+0x50b/0xd50 kernel/time/hrtimer.c:1811 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:kasan_quarantine_put+0x84/0x220 mm/kasan/quarantine.c:245 Code: e8 91 55 b5 ff 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 0f 85 83 00 00 00 41 f7 c7 00 02 00 00 74 01 fb 31 c0 <48> 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f c3 48 8d 80 00 67 03 00 45 RSP: 0018:ffffc900001e0808 EFLAGS: 00000206 RAX: f30585e924a90301 RBX: ffff88807df4bb40 RCX: f30585e924a90300 RDX: dffffc0000000000 RSI: ffffffff8a8c10a0 RDI: ffffffff8adf0d20 RBP: ffff88807df4bb40 R08: ffff8880b8f3580b R09: 1ffff110171e6b01 R10: dffffc0000000000 R11: ffffed10171e6b02 R12: 0000000000000000 R13: ffffc900001e08a0 R14: 00000000000843c0 R15: 0000000000000282 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] kmem_cache_free+0xf7/0x290 mm/slub.c:3709 llc_rcv+0x755/0xc60 net/llc/llc_input.c:-1 __netif_receive_skb_list_ptype net/core/dev.c:5655 [inline] __netif_receive_skb_list_core+0x6e6/0x750 net/core/dev.c:5698 __netif_receive_skb_list net/core/dev.c:5750 [inline] netif_receive_skb_list_internal+0x93f/0xca0 net/core/dev.c:5841 netif_receive_skb_list+0x51/0x4e0 net/core/dev.c:5893 ieee80211_rx_napi+0x357/0x3d0 net/mac80211/rx.c:5342 ieee80211_rx include/net/mac80211.h:4849 [inline] ieee80211_handle_queued_frames+0x105/0x1b0 net/mac80211/main.c:317 tasklet_action_common+0x2fe/0x4d0 kernel/softirq.c:827 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 df 0d 21 f7 65 8b 05 30 91 ca 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc9000cb97160 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a02 RCX: f30585e924a90300 RDX: dffffc0000000000 RSI: ffffffff8a8c10a0 RDI: 0000000000000001 RBP: ffffc9000cb971f8 R08: ffff8880b8f3580b R09: 1ffff110171e6b01 R10: dffffc0000000000 R11: ffffed10171e6b02 R12: dffffc0000000000 R13: ffff888023c70000 R14: ffffffff96e55910 R15: 1ffff92001972e2c __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] __kmem_cache_alloc_node+0x140/0x260 mm/slub.c:3398 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc+0xa0/0x240 mm/slab_common.c:949 kmalloc include/linux/slab.h:568 [inline] kzalloc include/linux/slab.h:699 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x27e/0x540 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x58e/0x5d0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x212/0x440 security/tomoyo/file.c:771 security_file_open+0x5e/0xa0 security/security.c:1682 do_dentry_open+0x305/0x10d0 fs/open.c:869 do_open fs/namei.c:3634 [inline] path_openat+0x2635/0x2ee0 fs/namei.c:3791 do_filp_open+0x1f1/0x430 fs/namei.c:3818 do_sys_openat2+0x150/0x4b0 fs/open.c:1320 do_sys_open fs/open.c:1336 [inline] __do_sys_openat fs/open.c:1352 [inline] __se_sys_openat fs/open.c:1347 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1347 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: 0033:0x7f5bbc99c819 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:00007f5bbd8ad028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f5bbcc16180 RCX: 00007f5bbc99c819 RDX: 00000000000026e1 RSI: 00002000000005c0 RDI: ffffffffffffff9c RBP: 00007f5bbca32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5bbcc16218 R14: 00007f5bbcc16180 R15: 00007ffc451acb68