BUG: soft lockup in neigh_timer_handler

Status: auto-obsoleted due to no activity on 2024/02/16 02:11
Reported-by: syzbot+f84dd713554c2eff91d5@syzkaller.appspotmail.com
First crash: 1004d, last: 982d
▶ ▼ Similar bugs (19)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: soft lockup in neigh_timer_handler (4) perf 1 1 120d 120d 0/29 closed as invalid on 2026/05/19 12:17
android-5-10 BUG: soft lockup in neigh_timer_handler 1 2 1068d 1076d 0/2 auto-obsoleted due to no activity on 2023/11/22 05:43
linux-4.19 BUG: soft lockup in neigh_timer_handler 1 4 1353d 1611d 0/1 auto-obsoleted due to no activity on 2023/03/12 06:57
android-54 BUG: soft lockup in neigh_timer_handler (2) 1 5 438d 523d 0/2 auto-obsoleted due to no activity on 2025/08/13 05:16
linux-4.14 BUG: soft lockup in neigh_timer_handler 1 3 1621d 1664d 0/1 auto-closed as invalid on 2022/06/16 21:59
android-5-15 BUG: soft lockup in neigh_timer_handler 1 1 16d 16d 0/2 premoderation: reported on 2026/07/10 13:24
upstream BUG: soft lockup in neigh_timer_handler (3) batman 1 2 449d 450d 0/29 auto-obsoleted due to no activity on 2025/08/01 18:42
upstream BUG: soft lockup in neigh_timer_handler (2) net 1 2 550d 580d 0/29 closed as invalid on 2025/02/28 15:46
android-54 BUG: soft lockup in neigh_timer_handler 1 3 766d 778d 0/2 auto-obsoleted due to no activity on 2024/09/18 13:19
upstream BUG: soft lockup in neigh_timer_handler net 1 1 1100d 1075d 0/29 auto-obsoleted due to no activity on 2023/10/20 21:15
linux-6.6 INFO: rcu detected stall in neigh_timer_handler 1 1 145d 145d 0/2 auto-obsoleted due to no activity on 2026/06/12 03:02
upstream INFO: rcu detected stall in neigh_timer_handler (8) net 1 C done done 72 714d 774d 28/29 fixed on 2024/10/21 12:45
linux-5.15 INFO: rcu detected stall in neigh_timer_handler 1 1 315d 315d 0/3 auto-obsoleted due to no activity on 2025/12/23 11:36
linux-6.6 INFO: rcu detected stall in neigh_timer_handler (2) 1 1 1d16h 1d16h 0/2 upstream: reported on 2026/07/25 18:11
linux-5.15 INFO: rcu detected stall in neigh_timer_handler (2) 1 2 152d 154d 0/3 auto-obsoleted due to no activity on 2026/06/04 18:05
linux-6.1 INFO: rcu detected stall in neigh_timer_handler (3) 1 1 285d 285d 0/3 auto-obsoleted due to no activity on 2026/01/23 04:30
upstream INFO: rcu detected stall in neigh_timer_handler (7) net 1 1 1931d 1931d 0/29 auto-closed as invalid on 2021/07/11 19:14
linux-6.1 INFO: rcu detected stall in neigh_timer_handler (2) 1 1 539d 539d 0/3 auto-obsoleted due to no activity on 2025/05/14 07:23
linux-6.1 INFO: rcu detected stall in neigh_timer_handler 1 4 670d 780d 0/3 auto-obsoleted due to no activity on 2025/01/03 05:12

Sample crash report:
watchdog: BUG: soft lockup - CPU#0 stuck for 143s! [swapper/0:0]
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G        W          6.1.43-syzkaller-00019-g1b639e97b8fc #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:kvm_wait+0x147/0x180 arch/x86/kernel/kvm.c:1066
Code: 4c 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 44 8b 74 24 1c 75 34 41 0f b6 45 00 44 38 f0 75 10 66 90 0f 00 2d ab 18 11 04 fb f4 <e9> 24 ff ff ff fb e9 1e ff ff ff 44 89 e9 80 e1 07 38 c1 7c a3 4c
RSP: 0018:ffffc90000007020 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 1ffff92000000e08 RCX: 1ffffffff0d9bc9d
RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffff8881f7037fd4
RBP: ffffc900000070d0 R08: dffffc0000000000 R09: ffffed103ee06ffb
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff8881f7037fd4 R14: 0000000000000001 R15: 1ffff92000000e0c
FS:  0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555556755430 CR3: 000000016c6e1000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 pv_wait arch/x86/include/asm/paravirt.h:603 [inline]
 pv_wait_node kernel/locking/qspinlock_paravirt.h:325 [inline]
 __pv_queued_spin_lock_slowpath+0x362/0xda0 kernel/locking/qspinlock.c:476
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock include/linux/spinlock.h:186 [inline]
 __raw_spin_lock include/linux/spinlock_api_smp.h:134 [inline]
 _raw_spin_lock+0x139/0x1b0 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:350 [inline]
 __dev_xmit_skb net/core/dev.c:3861 [inline]
 __dev_queue_xmit+0xd76/0x3700 net/core/dev.c:4234
 dev_queue_xmit include/linux/netdevice.h:3076 [inline]
 neigh_hh_output include/net/neighbour.h:536 [inline]
 neigh_output include/net/neighbour.h:550 [inline]
 ip6_finish_output2+0x1012/0x1820 net/ipv6/ip6_output.c:134
 __ip6_finish_output net/ipv6/ip6_output.c:195 [inline]
 ip6_finish_output+0x5d9/0xb60 net/ipv6/ip6_output.c:206
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0x1f7/0x4d0 net/ipv6/ip6_output.c:227
 dst_output include/net/dst.h:444 [inline]
 ip6_local_out+0x1ff/0x480 net/ipv6/output_core.c:161
 ip6_send_skb net/ipv6/ip6_output.c:1989 [inline]
 ip6_push_pending_frames+0x14a/0x290 net/ipv6/ip6_output.c:2009
 icmpv6_push_pending_frames+0x307/0x490 net/ipv6/icmp.c:303
 icmp6_send+0x1461/0x1e50 net/ipv6/icmp.c:622
 __icmpv6_send include/linux/icmpv6.h:28 [inline]
 icmpv6_send include/linux/icmpv6.h:49 [inline]
 ip6_link_failure+0x36/0x190 net/ipv6/route.c:2786
 dst_link_failure include/net/dst.h:423 [inline]
 ndisc_error_report+0x9a/0xd0 net/ipv6/ndisc.c:728
 neigh_invalidate+0x243/0x480 net/core/neighbour.c:1048
 neigh_timer_handler+0x778/0xe70 net/core/neighbour.c:1135
 call_timer_fn+0x3b/0x2d0 kernel/time/timer.c:1480
 expire_timers kernel/time/timer.c:1525 [inline]
 __run_timers+0x72a/0xa10 kernel/time/timer.c:1796
 run_timer_softirq+0x69/0xf0 kernel/time/timer.c:1809
 __do_softirq+0x1d8/0x661 kernel/softirq.c:617
 invoke_softirq kernel/softirq.c:472 [inline]
 __irq_exit_rcu+0x50/0xf0 kernel/softirq.c:700
 irq_exit_rcu+0x9/0x10 kernel/softirq.c:712
 sysvec_apic_timer_interrupt+0x9a/0xc0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:40 [inline]
RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:75 [inline]
RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:113 [inline]
RIP: 0010:acpi_idle_do_entry drivers/acpi/processor_idle.c:572 [inline]
RIP: 0010:acpi_idle_enter+0x416/0x760 drivers/acpi/processor_idle.c:709
Code: 89 de 48 83 e6 08 31 ff e8 97 43 79 fc 48 83 e3 08 0f 85 b1 00 00 00 0f 1f 44 00 00 e8 43 3f 79 fc 0f 00 2d ac 03 b4 00 fb f4 <fa> e9 e3 00 00 00 49 83 c7 04 4c 89 f8 48 c1 e8 03 42 0f b6 04 30
RSP: 0018:ffffffff86c07bd0 EFLAGS: 000002d3
RAX: ffffffff84fbb70d RBX: 0000000000000000 RCX: ffffffff86c1d4c0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffffff86c07c10 R08: ffffffff84fbb6f9 R09: fffffbfff0d83a99
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001
R13: ffff888109b54804 R14: dffffc0000000000 R15: ffff8881008af064
 cpuidle_enter_state+0x5eb/0x17f0 drivers/cpuidle/cpuidle.c:251
 cpuidle_enter+0x5f/0xa0 drivers/cpuidle/cpuidle.c:369
 call_cpuidle kernel/sched/idle.c:155 [inline]
 cpuidle_idle_call kernel/sched/idle.c:236 [inline]
 do_idle+0x3d1/0x580 kernel/sched/idle.c:303
 cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:400
 rest_init+0x10b/0x130 init/main.c:727
 arch_call_rest_init+0xe/0xe init/main.c:888
 start_kernel+0x46c/0x4d8 init/main.c:1143
 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:556
 x86_64_start_kernel+0x7c/0x81 arch/x86/kernel/head64.c:537
 secondary_startup_64_no_verify+0xce/0xdb
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 18499 Comm: syz-executor.1 Tainted: G        W          6.1.43-syzkaller-00019-g1b639e97b8fc #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:kvm_wait+0x147/0x180 arch/x86/kernel/kvm.c:1066
Code: 4c 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 44 8b 74 24 1c 75 34 41 0f b6 45 00 44 38 f0 75 10 66 90 0f 00 2d ab 18 11 04 fb f4 <e9> 24 ff ff ff fb e9 1e ff ff ff 44 89 e9 80 e1 07 38 c1 7c a3 4c
RSP: 0018:ffffc90004cb6be0 EFLAGS: 00000246
RAX: 0000000000000003 RBX: 1ffff92000996d80 RCX: ffffffff84fbfc6c
RDX: dffffc0000000000 RSI: 0000000000000003 RDI: ffff88810d8f78ac
RBP: ffffc90004cb6c90 R08: dffffc0000000000 R09: ffffed1021b1ef16
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff88810d8f78ac R14: 0000000000000003 R15: 1ffff92000996d84
FS:  00007efeefbf86c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020209000 CR3: 000000015c6b8000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 pv_wait arch/x86/include/asm/paravirt.h:603 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
 __pv_queued_spin_lock_slowpath+0x6de/0xda0 kernel/locking/qspinlock.c:511
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock include/linux/spinlock.h:186 [inline]
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:127 [inline]
 _raw_spin_lock_bh+0x139/0x1b0 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:355 [inline]
 get_dist_table+0x215/0x2e0 net/sched/sch_netem.c:798
 netem_change+0x9ec/0x20b0 net/sched/sch_netem.c:985
 netem_init+0x5b/0xb0 net/sched/sch_netem.c:1072
 qdisc_create+0x889/0x1160 net/sched/sch_api.c:1314
 tc_modify_qdisc+0x8d0/0x19c0
 rtnetlink_rcv_msg+0x9a5/0xca0 net/core/rtnetlink.c:6103
 netlink_rcv_skb+0x1cd/0x410 net/netlink/af_netlink.c:2525
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6121
 netlink_unicast_kernel net/netlink/af_netlink.c:1328 [inline]
 netlink_unicast+0x8ee/0xad0 net/netlink/af_netlink.c:1354
 netlink_sendmsg+0xa15/0xd30 net/netlink/af_netlink.c:1903
 sock_sendmsg_nosec net/socket.c:716 [inline]
 sock_sendmsg net/socket.c:736 [inline]
 ____sys_sendmsg+0x5dc/0x9d0 net/socket.c:2482
 ___sys_sendmsg net/socket.c:2536 [inline]
 __sys_sendmsg+0x2a9/0x390 net/socket.c:2565
 __do_sys_sendmsg net/socket.c:2574 [inline]
 __se_sys_sendmsg net/socket.c:2572 [inline]
 __x64_sys_sendmsg+0x7f/0x90 net/socket.c:2572
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7efeeee7cae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007efeefbf80c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007efeeef9bf80 RCX: 00007efeeee7cae9
RDX: 0000000000000000 RSI: 00000000200012c0 RDI: 0000000000000003
RBP: 00007efeeeec847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007efeeef9bf80 R15: 00007ffee6368888
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/11/18 02:06 android14-6.1 1b639e97b8fc cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 BUG: soft lockup in neigh_timer_handler
2023/10/27 02:49 android14-6.1 35361bdac25a bf285f0c .config console log report info ci2-android-6-1 BUG: soft lockup in neigh_timer_handler
* Struck through repros no longer work on HEAD.