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BUG: soft lockup in debug_check_no_obj_freed (2)

Status: closed as invalid on 2026/01/09 17:04
Subsystems: kernel
[Documentation on labels]
First crash: 38d, last: 38d
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: soft lockup in debug_check_no_obj_freed serial 1 syz 2 452d 452d 0/29 auto-obsoleted due to no activity on 2025/01/27 15:36
linux-6.6 INFO: rcu detected stall in debug_check_no_obj_freed origin:lts-only 1 C 1 32d 64d 0/2 upstream: reported C repro on 2025/11/11 10:45
linux-5.15 INFO: rcu detected stall in debug_check_no_obj_freed origin:lts-only 1 syz error 1 65d 65d 0/3 upstream: reported syz repro on 2025/11/10 02:51
upstream INFO: rcu detected stall in debug_check_no_obj_freed fs 1 1 346d 346d 0/29 auto-obsoleted due to no activity on 2025/05/03 06:53

Sample crash report:
watchdog: BUG: soft lockup - CPU#0 stuck for 143s! [syz.1.9481:9318]
Modules linked in:
irq event stamp: 14683301
hardirqs last  enabled at (14683300): [<ffffffff8b494f9d>] irqentry_exit+0x5dd/0x660 kernel/entry/common.c:219
hardirqs last disabled at (14683301): [<ffffffff8b49380e>] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1056
softirqs last  enabled at (14623500): [<ffffffff8185372a>] __do_softirq kernel/softirq.c:656 [inline]
softirqs last  enabled at (14623500): [<ffffffff8185372a>] invoke_softirq kernel/softirq.c:496 [inline]
softirqs last  enabled at (14623500): [<ffffffff8185372a>] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
softirqs last disabled at (14623503): [<ffffffff8185372a>] __do_softirq kernel/softirq.c:656 [inline]
softirqs last disabled at (14623503): [<ffffffff8185372a>] invoke_softirq kernel/softirq.c:496 [inline]
softirqs last disabled at (14623503): [<ffffffff8185372a>] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
CPU: 0 UID: 0 PID: 9318 Comm: syz.1.9481 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 eb 29 7d f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 73 e5 44 f6 65 8b 05 ec 12 2b 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc90000007620 EFLAGS: 00000206
RAX: df9123a5a0fb5900 RBX: 0000000000000a02 RCX: df9123a5a0fb5900
RDX: 0000000000000002 RSI: ffffffff8d76bd39 RDI: 0000000000000001
RBP: ffffc900000076a0 R08: ffffffff8f805a77 R09: 1ffffffff1f00b4e
R10: dffffc0000000000 R11: fffffbfff1f00b4f R12: dffffc0000000000
R13: ffff88806a2718c0 R14: ffffffff99b06690 R15: 1ffff92000000ec4
FS:  00007f75623c36c0(0000) GS:ffff8881260b1000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 000000007c99e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __debug_check_no_obj_freed lib/debugobjects.c:1108 [inline]
 debug_check_no_obj_freed+0x52e/0x550 lib/debugobjects.c:1129
 slab_free_hook mm/slub.c:2471 [inline]
 slab_free mm/slub.c:6663 [inline]
 kmem_cache_free+0x110/0x620 mm/slub.c:6774
 kfree_skb_reason include/linux/skbuff.h:1322 [inline]
 __netif_receive_skb_core+0x2a6e/0x2f90 net/core/dev.c:6111
 __netif_receive_skb_one_core net/core/dev.c:6135 [inline]
 __netif_receive_skb+0x72/0x380 net/core/dev.c:6250
 process_backlog+0x622/0x1500 net/core/dev.c:6602
 __napi_poll+0xae/0x320 net/core/dev.c:7666
 napi_poll net/core/dev.c:7729 [inline]
 net_rx_action+0x672/0xe50 net/core/dev.c:7881
 handle_softirqs+0x27d/0x850 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__schedule+0x4/0x5000 kernel/sched/core.c:6719
Code: f8 89 d9 48 8b 5c 24 08 e9 ee fe ff ff cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <55> 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec e0 01
RSP: 0018:ffffc90005d87598 EFLAGS: 00000286
RAX: df9123a5a0fb5900 RBX: 0000000000000000 RCX: df9123a5a0fb5900
RDX: 0000000000000006 RSI: ffffffff8d76bd39 RDI: 0000000000000001
RBP: ffffc90005d87640 R08: ffffffff8f805a77 R09: 1ffffffff1f00b4e
R10: dffffc0000000000 R11: fffffbfff1f00b4f R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000bb0eb4
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:preempt_schedule+0x0/0xc0 kernel/sched/core.c:7064
Code: 00 00 e8 63 51 46 f6 c3 cc cc cc cc cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 55 48 89 e5 41 56 53 48 83 e4 e0 48 83 ec 60 65 48 8b
RSP: 0018:ffffc90005d87750 EFLAGS: 00000283
RAX: ffffffff81b5c165 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000d499000 RSI: 00000000000043ac RDI: 00000000000043ad
RBP: ffffc90005d877a0 R08: ffffffff8f805a77 R09: 1ffffffff1f00b4e
R10: dffffc0000000000 R11: fffffbfff1f00b4f R12: 0000000000000000
R13: ffffffff927bed80 R14: 0000000000000000 R15: ffffffff81683e80
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 on_each_cpu_cond_mask+0x7a/0x80 kernel/smp.c:1044
 on_each_cpu include/linux/smp.h:71 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2711 [inline]
 smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2921
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 tracepoint_add_func+0x994/0xa10 kernel/tracepoint.c:315
 tracepoint_probe_register_prio kernel/tracepoint.c:464 [inline]
 tracepoint_probe_register+0x5d/0x90 kernel/tracepoint.c:484
 perf_trace_event_reg kernel/trace/trace_event_perf.c:129 [inline]
 perf_trace_event_init+0x4e1/0x9d0 kernel/trace/trace_event_perf.c:202
 perf_trace_init+0x23d/0x2d0 kernel/trace/trace_event_perf.c:226
 perf_tp_event_init+0x8d/0x120 kernel/events/core.c:10943
 perf_try_init_event+0x17f/0x870 kernel/events/core.c:12686
 perf_init_event kernel/events/core.c:12784 [inline]
 perf_event_alloc+0x1430/0x2d50 kernel/events/core.c:13059
 __do_sys_perf_event_open kernel/events/core.c:13577 [inline]
 __se_sys_perf_event_open+0x756/0x1d90 kernel/events/core.c:13458
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f756158f749
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:00007f75623c3038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f75617e5fa0 RCX: 00007f756158f749
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000040
RBP: 00007f7561613f91 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f75617e6038 R14: 00007f75617e5fa0 R15: 00007ffdc09bdaa8
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 9311 Comm: syz.9.9477 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__read_once_word_nocheck+0x3/0x10 include/asm-generic/rwonce.h:67
Code: b3 00 48 ba 00 00 00 00 00 fc ff df e9 88 fc ff ff 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 8b 07 <e9> 58 0b d8 09 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000a07cc8 EFLAGS: 00000202
RAX: ffffffff892ede19 RBX: ffffc90000a08b18 RCX: 1ffff92000140f01
RDX: ffffffff909809fc RSI: 0000000000000002 RDI: ffffc90000a08b18
RBP: 1ffff92000140fc1 R08: 0000000000000001 R09: ffffffff8df41cc0
R10: ffffc90000a07e50 R11: fffff52000140fcc R12: ffffc90000a09000
R13: 1ffff92000140fc2 R14: ffffc90000a07e00 R15: ffffc90000a01000
FS:  00007f9afbbf66c0(0000) GS:ffff8881261b1000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcaa88ce040 CR3: 000000004cc8a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000200000000300
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 deref_stack_reg arch/x86/kernel/unwind_orc.c:406 [inline]
 unwind_next_frame+0xc3c/0x2390 arch/x86/kernel/unwind_orc.c:585
 perf_callchain_kernel+0x3ac/0x600 arch/x86/events/core.c:2813
 get_perf_callchain+0x23c/0x820 kernel/events/callchain.c:244
 ____bpf_get_stackid kernel/bpf/stackmap.c:337 [inline]
 bpf_get_stackid+0x113/0x1e0 kernel/bpf/stackmap.c:323
 ____bpf_get_stackid_raw_tp kernel/trace/bpf_trace.c:1628 [inline]
 bpf_get_stackid_raw_tp+0x196/0x210 kernel/trace/bpf_trace.c:1617
 bpf_prog_53f0063d4d7f65ce+0x2a/0x32
 bpf_dispatcher_nop_func include/linux/bpf.h:1376 [inline]
 __bpf_prog_run include/linux/filter.h:723 [inline]
 bpf_prog_run include/linux/filter.h:730 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline]
 bpf_trace_run3+0x298/0x4f0 kernel/trace/bpf_trace.c:2117
 __do_trace_kmem_cache_free include/trace/events/kmem.h:117 [inline]
 trace_kmem_cache_free include/trace/events/kmem.h:117 [inline]
 kmem_cache_free+0x5ae/0x620 mm/slub.c:6773
 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1107
 skb_release_all net/core/skbuff.c:1182 [inline]
 __kfree_skb net/core/skbuff.c:1196 [inline]
 sk_skb_reason_drop+0x127/0x170 net/core/skbuff.c:1234
 kfree_skb_reason include/linux/skbuff.h:1322 [inline]
 tcf_kfree_skb_list include/net/sch_generic.h:1127 [inline]
 __dev_xmit_skb net/core/dev.c:4258 [inline]
 __dev_queue_xmit+0x2622/0x3140 net/core/dev.c:4783
 dev_queue_xmit include/linux/netdevice.h:3381 [inline]
 neigh_hh_output include/net/neighbour.h:540 [inline]
 neigh_output include/net/neighbour.h:554 [inline]
 ip6_finish_output2+0xf70/0x1480 net/ipv6/ip6_output.c:136
 NF_HOOK_COND include/linux/netfilter.h:307 [inline]
 ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247
 ip6_send_skb+0x1d5/0x390 net/ipv6/ip6_output.c:1994
 icmp6_send+0x12fe/0x1990 net/ipv6/icmp.c:827
 __icmpv6_send include/linux/icmpv6.h:28 [inline]
 icmpv6_send include/linux/icmpv6.h:49 [inline]
 ip6_link_failure+0x3b/0x4c0 net/ipv6/route.c:2843
 dst_link_failure include/net/dst.h:432 [inline]
 ndisc_error_report+0x118/0x160 net/ipv6/ndisc.c:732
 neigh_invalidate+0x235/0x460 net/core/neighbour.c:1081
 neigh_timer_handler+0x949/0x1130 net/core/neighbour.c:1172
 call_timer_fn+0x16e/0x590 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x61a/0x860 kernel/time/timer.c:2385
 run_timer_base kernel/time/timer.c:2394 [inline]
 run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2404
 handle_softirqs+0x27d/0x850 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:finish_task_switch+0x242/0x940 kernel/sched/core.c:5114
Code: 0f 84 c2 01 00 00 48 85 db 0f 85 e9 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 68 13 ba 09 e8 33 3e 37 00 fb 4c 8b 65 c0 <49> 8d bc 24 48 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc90005797418 EFLAGS: 00000286
RAX: 5b4d9a752df34700 RBX: 0000000000000000 RCX: 5b4d9a752df34700
RDX: 0000000000000007 RSI: ffffffff8d76bd39 RDI: ffffffff8bbfc660
RBP: ffffc90005797470 R08: ffffffff8f805a77 R09: 1ffffffff1f00b4e
R10: dffffc0000000000 R11: fffffbfff1f00b4f R12: ffff88807a530000
R13: dffffc0000000000 R14: ffff888046959e80 R15: ffff8880b893b358
 context_switch kernel/sched/core.c:5259 [inline]
 __schedule+0x14c4/0x5000 kernel/sched/core.c:6863
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:qlink_to_object mm/kasan/quarantine.c:140 [inline]
RIP: 0010:qlink_free mm/kasan/quarantine.c:145 [inline]
RIP: 0010:qlist_free_all+0x6d/0x100 mm/kasan/quarantine.c:179
Code: 0c 04 49 8b 44 04 08 48 89 c2 48 ff ca a8 01 48 0f 44 d1 0f b6 42 33 c1 e0 18 3d 00 00 00 f5 49 0f 45 d5 4c 8b 62 08 49 8b 2f <49> 63 84 24 d8 00 00 00 49 29 c7 4c 89 e7 4c 89 fe e8 4d e3 ff ff
RSP: 0018:ffffc90005797860 EFLAGS: 00000246
RAX: 00000000f5000000 RBX: ffffc90005797898 RCX: ffffea00012d6c80
RDX: ffffea00012d6c80 RSI: 000000000003cecc RDI: 000000000003cecd
RBP: ffff88804b5b22d8 R08: 0000000000000001 R09: ffffffff8227414c
R10: dffffc0000000000 R11: fffffbfff1f00b4f R12: ffff88801a030a00
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88804b5b2a28
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:352
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4948 [inline]
 slab_alloc_node mm/slub.c:5258 [inline]
 __do_kmalloc_node mm/slub.c:5651 [inline]
 __kmalloc_node_track_caller_noprof+0x51d/0x810 mm/slub.c:5759
 kmemdup_noprof+0x2b/0x70 mm/util.c:138
 kmemdup_noprof include/linux/fortify-string.h:765 [inline]
 neigh_parms_alloc+0x87/0x510 net/core/neighbour.c:1747
 inetdev_init+0x118/0x4e0 net/ipv4/devinet.c:280
 inetdev_event+0x2f1/0x1570 net/ipv4/devinet.c:1590
 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
 call_netdevice_notifiers net/core/dev.c:2282 [inline]
 register_netdevice+0x15bd/0x1a70 net/core/dev.c:11429
 tun_set_iff+0x844/0xf00 drivers/net/tun.c:2807
 __tun_chr_ioctl+0x788/0x1df0 drivers/net/tun.c:3088
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9afd98f749
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:00007f9afbbf6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f9afdbe5fa0 RCX: 00007f9afd98f749
RDX: 00002000000000c0 RSI: 00000000400454ca RDI: 0000000000000008
RBP: 00007f9afda13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9afdbe6038 R14: 00007f9afdbe5fa0 R15: 00007ffe227f3428
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/06 19:55 bpf 861111b69896 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce BUG: soft lockup in debug_check_no_obj_freed
* Struck through repros no longer work on HEAD.