syzbot


BUG: soft lockup in addrconf_rs_timer (3)

Status: premoderation: reported on 2026/04/20 17:07
Reported-by: syzbot+f63976ac8691c3ebbefc@syzkaller.appspotmail.com
First crash: 8h15m, last: 8h15m
Similar bugs (25)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: soft lockup in addrconf_rs_timer (3) net 1 syz 8 936d 1000d 0/29 auto-obsoleted due to no activity on 2024/01/05 16:48
upstream BUG: soft lockup in addrconf_rs_timer (4) net 1 1 831d 831d 0/29 closed as invalid on 2024/03/12 13:17
android-6-1 BUG: soft lockup in addrconf_rs_timer 1 1 904d 904d 0/2 auto-obsoleted due to no activity on 2024/01/27 13:54
android-5-10 BUG: soft lockup in addrconf_rs_timer (2) 1 C 265 336d 667d 0/2 auto-obsoleted due to no activity on 2025/07/28 18:01
android-6-1 BUG: soft lockup in addrconf_rs_timer (5) 1 1 1d07h 1d07h 0/2 premoderation: reported on 2026/04/19 17:29
android-5-10 BUG: soft lockup in addrconf_rs_timer 1 2 994d 1013d 0/2 auto-obsoleted due to no activity on 2023/10/29 01:38
linux-6.1 BUG: soft lockup in addrconf_rs_timer 1 C done 26 1042d 1054d 3/3 fixed on 2023/07/30 15:47
linux-4.19 BUG: soft lockup in addrconf_rs_timer 1 syz error 24 1176d 1858d 0/1 upstream: reported syz repro on 2021/03/19 06:05
linux-4.14 BUG: soft lockup in addrconf_rs_timer 1 C error 133 1214d 2416d 0/1 upstream: reported C repro on 2019/09/08 14:09
android-5-10 BUG: soft lockup in addrconf_rs_timer (3) 1 1 75d 75d 0/2 premoderation: reported on 2026/02/04 01:38
linux-5.15 BUG: soft lockup in addrconf_rs_timer 1 C error 36 1041d 1054d 0/3 auto-obsoleted due to no activity on 2023/08/23 09:06
android-5-15 BUG: soft lockup in addrconf_rs_timer (2) 1 syz 99 480d 723d 0/2 auto-obsoleted due to no activity on 2025/02/14 09:13
android-6-1 BUG: soft lockup in addrconf_rs_timer (3) 1 1 381d 381d 0/2 auto-obsoleted due to no activity on 2025/07/03 20:11
linux-6.6 INFO: rcu detected stall in addrconf_rs_timer origin:lts-only 1 C error 11 17h51m 142d 0/2 upstream: reported C repro on 2025/11/29 19:55
android-54 BUG: soft lockup in addrconf_rs_timer 1 190 656d 711d 0/2 auto-obsoleted due to no activity on 2024/08/22 17:20
upstream BUG: soft lockup in addrconf_rs_timer net 1 18 2220d 2416d 0/29 auto-closed as invalid on 2020/07/20 22:25
android-6-1 BUG: soft lockup in addrconf_rs_timer (2) 1 syz 176 501d 707d 0/2 auto-obsoleted due to no activity on 2025/01/24 01:43
upstream BUG: soft lockup in addrconf_rs_timer (2) net 1 C 51 1034d 1055d 23/29 fixed on 2023/07/04 09:17
android-6-1 BUG: soft lockup in addrconf_rs_timer (4) 1 7 104d 252d 0/2 auto-obsoleted due to no activity on 2026/04/06 21:21
android-5-15 BUG: soft lockup in addrconf_rs_timer 1 1 1002d 1002d 0/2 auto-obsoleted due to no activity on 2023/10/21 14:14
upstream INFO: rcu detected stall in addrconf_rs_timer (4) net 1 C error error 121 1632d 2086d 0/29 closed as invalid on 2022/02/08 10:39
linux-6.1 INFO: rcu detected stall in addrconf_rs_timer origin:lts-only 1 C done 98 40d 696d 0/3 upstream: reported C repro on 2024/05/24 18:08
linux-5.15 INFO: rcu detected stall in addrconf_rs_timer origin:lts-only 1 C error 97 1d00h 862d 0/3 upstream: reported C repro on 2023/12/10 10:27
upstream INFO: rcu detected stall in addrconf_rs_timer (6) virt mm netfilter 1 syz error error 701 6d15h 688d 0/29 upstream: reported syz repro on 2024/06/01 13:51
upstream INFO: rcu detected stall in addrconf_rs_timer (5) kvm 1 4 1456d 1456d 0/29 auto-closed as invalid on 2022/06/24 22:41

Sample crash report:
RBP: 00007fc08ccd8c91 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc08cebc038 R14: 00007fc08cebbfa0 R15: 00007fff2ab443c8
 </TASK>
watchdog: BUG: soft lockup - CPU#1 stuck for 267s! [syz.3.423:1856]
Modules linked in:
CPU: 1 PID: 1856 Comm: syz.3.423 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:call_rcu+0xbfd/0xf80 kernel/rcu/tree.c:3130
Code: 80 3c 03 00 74 08 4c 89 f7 e8 cf 0d 52 00 48 8b 05 38 a5 23 05 49 03 06 49 39 c5 7f 52 fb 48 c7 84 24 80 00 00 00 0e 36 e0 45 <48> b8 00 00 00 00 00 fc ff df 48 8b 4c 24 50 48 c7 04 01 00 00 00
RSP: 0018:ffffc900001d0260 EFLAGS: 00000283
RAX: 0000000000002710 RBX: 1ffff1103ee27187 RCX: ffffffff8156e776
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8881f7138c08
RBP: ffffc900001d0388 R08: ffff8881f7138c0f R09: 1ffff1103ee27181
R10: dffffc0000000000 R11: ffffed103ee27182 R12: ffff8881f7138c08
R13: 000000000000014e R14: ffff8881f7138c38 R15: 1ffff1103ee27181
FS:  00007fc08b69d6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558ec544e8 CR3: 000000012b186000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 call_rcu_hurry include/linux/rcupdate.h:90 [inline]
 dst_release+0x123/0x190 net/core/dst.c:181
 refdst_drop include/net/dst.h:255 [inline]
 skb_dst_drop include/net/dst.h:267 [inline]
 __dev_queue_xmit+0x7b7/0x2da0 net/core/dev.c:4265
 dev_queue_xmit+0x17/0x20 net/core/dev.c:4355
 neigh_resolve_output+0x6cf/0x770 net/core/neighbour.c:1504
 neigh_output include/net/neighbour.h:517 [inline]
 ip6_finish_output2+0x10b6/0x17a0 net/ipv6/ip6_output.c:130
 __ip6_finish_output+0x61e/0x7d0 net/ipv6/ip6_output.c:201
 ip6_finish_output+0x31/0x240 net/ipv6/ip6_output.c:211
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0x1fa/0x410 net/ipv6/ip6_output.c:234
 dst_output include/net/dst.h:453 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ndisc_send_skb+0x80d/0xd10 net/ipv6/ndisc.c:513
 ndisc_send_rs+0x6e5/0x960 net/ipv6/ndisc.c:707
 addrconf_rs_timer+0x2cf/0x610 net/ipv6/addrconf.c:3980
 call_timer_fn+0x38/0x290 kernel/time/timer.c:1459
 expire_timers kernel/time/timer.c:1504 [inline]
 __run_timers+0x650/0x9e0 kernel/time/timer.c:1775
 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1788
 handle_softirqs+0x250/0x560 kernel/softirq.c:583
 __do_softirq kernel/softirq.c:621 [inline]
 invoke_softirq kernel/softirq.c:443 [inline]
 __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:670
 irq_exit_rcu+0x9/0x10 kernel/softirq.c:682
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa9/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:find_stack lib/stackdepot.c:207 [inline]
RIP: 0010:__stack_depot_save+0x16e/0x480 lib/stackdepot.c:304
Code: 29 d1 41 31 cd c1 c1 18 41 29 cd 48 8b 3d 02 3d a5 04 45 89 e9 41 81 e1 ff 0f 00 00 4e 8b 24 cf 4d 85 e4 74 5c 44 89 f1 eb 09 <4d> 8b 24 24 4d 85 e4 74 4e 45 39 6c 24 08 75 f0 45 39 74 24 0c 75
RSP: 0018:ffffc90001117478 EFLAGS: 00000206
RAX: 0000000000000000 RBX: ffffc900011174e0 RCX: 0000000000000013
RDX: 000000006b1cefe5 RSI: 000000006065db3d RDI: ffff88823fec0000
RBP: ffffc900011174d0 R08: 0000000000000001 R09: 0000000000000aa7
R10: 00000000be21117f R11: ffffed10215c2c59 R12: ffff88812b13cd70
R13: 0000000001386aa7 R14: 0000000000000013 R15: 0000000000000800
 kasan_save_stack mm/kasan/common.c:39 [inline]
 kasan_set_track+0x5b/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:365
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373
 kasan_slab_free include/linux/kasan.h:193 [inline]
 slab_free_hook mm/slub.c:1728 [inline]
 slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754
 slab_free mm/slub.c:3526 [inline]
 kmem_cache_free+0x100/0x320 mm/slub.c:3544
 __mmdrop+0x304/0x410 kernel/fork.c:755
 mmdrop include/linux/sched/mm.h:49 [inline]
 finish_task_switch+0x2bb/0x780 kernel/sched/core.c:5075
 context_switch kernel/sched/core.c:5181 [inline]
 __schedule+0xb76/0x14c0 kernel/sched/core.c:6538
 preempt_schedule_common+0x9b/0xf0 kernel/sched/core.c:6714
 preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6739
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 smp_call_function_single+0x3f7/0x490 kernel/smp.c:760
 task_function_call kernel/events/core.c:119 [inline]
 perf_install_in_context+0x4b8/0x760 kernel/events/core.c:2990
 __do_sys_perf_event_open kernel/events/core.c:12645 [inline]
 __se_sys_perf_event_open+0x12b1/0x1bb0 kernel/events/core.c:12239
 __x64_sys_perf_event_open+0xbf/0xd0 kernel/events/core.c:12239
 x64_sys_call+0x50d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:299
 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: 0033:0x7fc08cc42819
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:00007fc08b69d028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fc08cebbfa0 RCX: 00007fc08cc42819
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000100
RBP: 00007fc08ccd8c91 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc08cebc038 R14: 00007fc08cebbfa0 R15: 00007fff2ab443c8
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 10 Comm: kworker/u4:1 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_many_cond+0x8e3/0xa10 kernel/smp.c:969
Code: 84 c0 0f 85 9d 00 00 00 41 8b 1f 89 de 83 e6 01 31 ff e8 e0 4e 0a 00 83 e3 01 48 8b 5c 24 10 75 07 e8 21 4b 0a 00 eb 42 f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 10 41 f7
RSP: 0018:ffffc900000a7860 EFLAGS: 00000293
RAX: ffffffff815f7be5 RBX: ffff8881f7038e80 RCX: ffff888100273b40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900000a7978 R08: ffffffff86e947ef R09: 1ffffffff0dd28fd
R10: dffffc0000000000 R11: fffffbfff0dd28fe R12: 1ffff1103ee071d0
R13: 1ffff1103ee2784d R14: 0000000000000001 R15: ffff8881f713c268
FS:  0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f98d187d218 CR3: 000000000660f000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x43/0x80 kernel/smp.c:1134
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:1442 [inline]
 text_poke_bp_batch+0x1d4/0x600 arch/x86/kernel/alternative.c:1642
 text_poke_flush arch/x86/kernel/alternative.c:1833 [inline]
 text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:1840
 arch_jump_label_transform_apply+0x15/0x30 arch/x86/kernel/jump_label.c:146
 __jump_label_update+0x37c/0x3a0 kernel/jump_label.c:459
 jump_label_update+0x39b/0x450 kernel/jump_label.c:830
 static_key_disable_cpuslocked+0xc5/0x1a0 kernel/jump_label.c:207
 static_key_disable+0x1a/0x30 kernel/jump_label.c:215
 toggle_allocation_gate+0x3af/0x440 mm/kfence/core.c:797
 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325
 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472
 kthread+0x411/0x500 kernel/kthread.c:337
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/20 17:06 android13-5.15-lts 7fad219d720d e65da4ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15-perf BUG: soft lockup in addrconf_rs_timer
* Struck through repros no longer work on HEAD.