BUG: soft lockup in kthreadd (2)

Status: auto-obsoleted due to no activity on 2025/03/25 17:14
Reported-by: syzbot+ede607413377ca875d26@syzkaller.appspotmail.com
First crash: 611d, last: 611d
▶ ▼ Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 BUG: soft lockup in kthreadd origin:lts 1 syz, C 2 761d 782d 0/2 auto-obsoleted due to no activity on 2024/11/05 13:04
linux-6.6 INFO: rcu detected stall in kthreadd 1 1 369d 369d 0/2 auto-obsoleted due to no activity on 2025/12/02 17:39
linux-6.1 INFO: rcu detected stall in kthreadd 1 1 835d 835d 0/3 auto-obsoleted due to no activity on 2024/08/23 07:20
upstream INFO: rcu detected stall in kthreadd (2) mm 1 syz, C unreliable error 139 2d16h 668d 0/29 upstream: reported C repro on 2024/10/30 03:07
linux-6.6 INFO: rcu detected stall in kthreadd (2) 1 4 10d 213d 0/2 upstream: reported on 2026/01/27 21:22
upstream INFO: rcu detected stall in kthreadd mm 1 2 855d 866d 0/29 auto-obsoleted due to no activity on 2024/07/25 04:06

Sample crash report:
watchdog: BUG: soft lockup - CPU#0 stuck for 246s! [kthreadd:2]
Modules linked in:
CPU: 0 PID: 2 Comm: kthreadd Not tainted 5.15.173-syzkaller-00161-gb4bd207b0380 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:trylock_clear_pending kernel/locking/qspinlock_paravirt.h:121 [inline]
RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:435 [inline]
RIP: 0010:__pv_queued_spin_lock_slowpath+0x5cc/0xc40 kernel/locking/qspinlock.c:508
Code: c0 0f 85 48 01 00 00 48 8b 44 24 08 c6 00 01 bb 00 80 ff ff eb 06 f3 90 ff c3 74 5e 41 0f b6 44 15 00 84 c0 75 36 41 80 3f 00 <75> ea 4c 89 ff be 02 00 00 00 e8 25 8a 5d 00 48 ba 00 00 00 00 00
RSP: 0018:ffffc900000275e0 EFLAGS: 00000202
RAX: 0000000000000004 RBX: 00000000ffffebb3 RCX: 000000008750b600
RDX: dffffc0000000000 RSI: 0000000000000003 RDI: ffffffff8750b640
RBP: ffffc900000276d0 R08: dffffc0000000000 R09: 0000000000000000
R10: fffffbfff0ea16c8 R11: dffffc0000000001 R12: ffff8881f7038ad4
R13: 1ffffffff0ea16c8 R14: 1ffff1103ee00001 R15: ffffffff8750b640
FS:  0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffe78ccd68 CR3: 00000001420b9000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock include/linux/spinlock.h:187 [inline]
 __raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_lock+0x139/0x1b0 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:363 [inline]
 preload_this_cpu_lock mm/vmalloc.c:1511 [inline]
 alloc_vmap_area+0x653/0x1a80 mm/vmalloc.c:1553
 __get_vm_area_node+0x158/0x360 mm/vmalloc.c:2439
 __vmalloc_node_range+0xe2/0x8d0 mm/vmalloc.c:3051
 alloc_thread_stack_node kernel/fork.c:255 [inline]
 dup_task_struct+0x416/0xc60 kernel/fork.c:945
 copy_process+0x5c4/0x3290 kernel/fork.c:2092
 kernel_clone+0x21e/0x9e0 kernel/fork.c:2661
 kernel_thread+0x168/0x1e0 kernel/fork.c:2722
 create_kthread kernel/kthread.c:360 [inline]
 kthreadd+0x35b/0x490 kernel/kthread.c:717
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3919 Comm: syz.0.626 Not tainted 5.15.173-syzkaller-00161-gb4bd207b0380 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x1/0x90 kernel/kcov.c:292
Code: 03 00 00 00 48 89 44 0a 10 48 89 74 0a 18 4c 89 44 0a 20 49 ff c1 4c 89 09 5d c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 55 <48> 89 e5 4c 8b 45 08 65 48 8b 15 10 03 92 7e 65 8b 05 11 03 92 7e
RSP: 0018:ffffc900001d0098 EFLAGS: 00000046
RAX: ffffffff817e3b84 RBX: 0000000000000001 RCX: ffff88812db2a780
RDX: 0000000000010100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900001d00d8 R08: ffffffff817e3b7a R09: ffffed1025ce798e
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: 0000000000000020 R14: 0000000000000020 R15: ffff88812e73cc68
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc359ac41b8 CR3: 000000011d1d8000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __perf_event_overflow+0x2b4/0x390 kernel/events/core.c:9344
 perf_swevent_hrtimer+0x3fd/0x560 kernel/events/core.c:10736
 __run_hrtimer kernel/time/hrtimer.c:1687 [inline]
 __hrtimer_run_queues+0x41a/0xad0 kernel/time/hrtimer.c:1751
 hrtimer_interrupt+0x40c/0xaa0 kernel/time/hrtimer.c:1813
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0xfb/0x3f0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x53/0xc0 arch/x86/kernel/apic/apic.c:1108
 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:check_kcov_mode kernel/kcov.c:172 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x2e/0x60 kernel/kcov.c:206
Code: 48 8b 45 08 65 48 8b 0d c0 06 92 7e 65 8b 15 c1 06 92 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 5c 0b 00 00 00 <74> 2c 8b 91 38 0b 00 00 83 fa 02 75 21 48 8b 91 40 0b 00 00 48 8b
RSP: 0018:ffffc900001d0700 EFLAGS: 00000246
RAX: ffffffff84668ba9 RBX: 0000000000000001 RCX: ffff88812db2a780
RDX: 0000000000000100 RSI: ffffffff85d9e380 RDI: ffffffff85a34500
RBP: ffffc900001d0700 R08: ffffffff84667fa7 R09: ffffc900001d0870
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8881266862b0
R13: dffffc0000000000 R14: ffffffff872aa140 R15: ffff888126686378
 local_bh_enable+0x9/0x30 include/linux/bottom_half.h:31
 ip6t_do_table+0x1635/0x1850 net/ipv6/netfilter/ip6_tables.c:377
 ip6t_mangle_out net/ipv6/netfilter/ip6table_mangle.c:49 [inline]
 ip6table_mangle_hook+0x20d/0x790 net/ipv6/netfilter/ip6table_mangle.c:71
 nf_hook_entry_hookfn include/linux/netfilter.h:143 [inline]
 nf_hook_slow+0xbe/0x200 net/netfilter/core.c:590
 nf_hook include/linux/netfilter.h:260 [inline]
 NF_HOOK include/linux/netfilter.h:303 [inline]
 ndisc_send_skb+0xc31/0xc90 net/ipv6/ndisc.c:511
 ndisc_send_rs+0x532/0x6a0 net/ipv6/ndisc.c:705
 addrconf_rs_timer+0x2d1/0x600 net/ipv6/addrconf.c:3979
 call_timer_fn+0x3b/0x2d0 kernel/time/timer.c:1457
 expire_timers kernel/time/timer.c:1502 [inline]
 __run_timers+0x72a/0xa10 kernel/time/timer.c:1773
 run_timer_softirq+0x69/0xf0 kernel/time/timer.c:1786
 handle_softirqs+0x25e/0x5c0 kernel/softirq.c:565
 __do_softirq kernel/softirq.c:603 [inline]
 invoke_softirq kernel/softirq.c:425 [inline]
 __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:652
 irq_exit_rcu+0x9/0x10 kernel/softirq.c:664
 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:__pv_queued_spin_lock_slowpath+0x8ea/0xc40 kernel/locking/qspinlock.c:560
Code: df 75 27 41 0f b6 44 15 00 84 c0 0f 85 89 02 00 00 41 c6 07 03 4c 89 ff 48 89 de e8 00 04 00 00 48 ba 00 00 00 00 00 fc ff df <48> c7 c7 c0 e8 48 85 48 89 d3 e8 57 47 8c 03 65 ff 0d ec 50 ae 7e
RSP: 0018:ffffc90000bf7460 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff8881f7138ad4 RCX: ffffffff81553201
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffffffff8750b640
RBP: ffffc90000bf7550 R08: dffffc0000000000 R09: 0000000000000000
R10: fffffbfff0ea16c8 R11: dffffc0000000001 R12: 0000000000040000
R13: 1ffffffff0ea16c8 R14: 1ffff1103ee27159 R15: ffffffff8750b640
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock include/linux/spinlock.h:187 [inline]
 __raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_lock+0x139/0x1b0 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:363 [inline]
 __cond_resched_lock+0x61/0x90 kernel/sched/core.c:8459
 __purge_vmap_area_lazy+0x15a9/0x1690 mm/vmalloc.c:1721
 try_purge_vmap_area_lazy+0x38/0x50 mm/vmalloc.c:1734
 free_vmap_area_noflush+0x9df/0xa20 mm/vmalloc.c:1776
 free_unmap_vmap_area mm/vmalloc.c:1789 [inline]
 remove_vm_area+0x1d9/0x200 mm/vmalloc.c:2544
 vm_remove_mappings mm/vmalloc.c:2573 [inline]
 __vunmap+0x24b/0x8f0 mm/vmalloc.c:2642
 __vfree mm/vmalloc.c:2700 [inline]
 vfree+0x7f/0xb0 mm/vmalloc.c:2731
 kcov_put kernel/kcov.c:417 [inline]
 kcov_close+0x2b/0x50 kernel/kcov.c:519
 __fput+0x228/0x8c0 fs/file_table.c:280
 ____fput+0x15/0x20 fs/file_table.c:308
 task_work_run+0x129/0x190 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0xc48/0x2ca0 kernel/exit.c:880
 do_group_exit+0x141/0x310 kernel/exit.c:1002
 get_signal+0x7a3/0x1630 kernel/signal.c:2907
 arch_do_signal_or_restart+0xbd/0x1680 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0xa0/0xe0 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:214
 irqentry_exit_to_user_mode+0x9/0x10 kernel/entry/common.c:320
 irqentry_exit+0x12/0x40 kernel/entry/common.c:411
 sysvec_apic_timer_interrupt+0x64/0xc0 arch/x86/kernel/apic/apic.c:1108
 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0033:0x7fd0bc428d29
Code: Unable to access opcode bytes at RIP 0x7fd0bc428cff.
RSP: 002b:00007fd0baa580e8 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 00007fd0bc619168 RCX: 00007fd0bc428d29
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fd0bc61916c
RBP: 00007fd0bc619160 R08: 00007fffff56a0b0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd0bc61916c
R13: 0000000000000000 R14: 00007fffff5032d0 R15: 00007fffff5033b8
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/12/25 17:07 android13-5.15-lts b4bd207b0380 444551c4 .config console log report info ci2-android-5-15-perf BUG: soft lockup in kthreadd
* Struck through repros no longer work on HEAD.