syzbot

 sign-in | mailing list | source | docs
🐞 Open [706]
🐞 Fixed [58]
🐞 Invalid [596]
⬇ Missing Backports [56]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
💬 Send us feedback

INFO: rcu detected stall in call_usermodehelper_exec_async

Status: auto-obsoleted due to no activity on 2023/10/09 16:55
Reported-by: syzbot+c4c56f24162138ad346a@syzkaller.appspotmail.com
First crash: 508d, last: 508d
▶ ▼ Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: rcu detected stall in call_usermodehelper_exec_async 1 166d 166d 0/3 auto-obsoleted due to no activity on 2024/09/16 03:00
upstream INFO: rcu detected stall in call_usermodehelper_exec_async kernel 1 1815d 1815d 0/28 closed as invalid on 2019/12/04 14:14
upstream INFO: rcu detected stall in call_usermodehelper_exec_async (2) cgroups mm 1 905d 905d 0/28 auto-closed as invalid on 2022/08/28 20:38
upstream BUG: soft lockup in call_usermodehelper_exec_async mm 2 1111d 1161d 0/28 closed as dup on 2021/09/17 07:37

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (1 ticks this GP) idle=477/1/0x4000000000000000 softirq=129255/129260 fqs=0 
	(t=11641 jiffies g=182949 q=66)
rcu: rcu_preempt kthread timer wakeup didn't happen for 11640 jiffies! g182949 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=101680
rcu: rcu_preempt kthread starved for 11641 jiffies! g182949 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:25984 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0x12c4/0x4590 kernel/sched/core.c:6372
 schedule+0x11b/0x1f0 kernel/sched/core.c:6455
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1884
 rcu_gp_fqs_loop+0x2af/0xf70 kernel/rcu/tree.c:1959
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2132
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3589 Comm: kworker/1:5 Not tainted 5.15.119-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Workqueue: events bpf_prog_free_deferred
RIP: 0010:rep_nop arch/x86/include/asm/vdso/processor.h:13 [inline]
RIP: 0010:cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline]
RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_many_cond+0xa91/0xd90 kernel/smp.c:969
Code: 0f b6 04 03 84 c0 0f 85 84 00 00 00 45 8b 7d 00 44 89 fe 83 e6 01 31 ff e8 1c b9 0b 00 41 83 e7 01 75 07 e8 b1 b5 0b 00 eb 41 <f3> 90 48 b8 00 00 00 00 00 fc ff df 0f b6 04 03 84 c0 75 11 41 f7
RSP: 0018:ffffc900031af8a0 EFLAGS: 00000293
RAX: ffffffff81744b14 RBX: 1ffff11017348371 RCX: ffff888019690000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900031af9e0 R08: ffffffff81744ae4 R09: fffffbfff1f79821
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: ffff8880b9a41b88 R14: ffff8880b9b3a700 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa59d241718 CR3: 0000000078507000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1135
 __purge_vmap_area_lazy+0x294/0x1740 mm/vmalloc.c:1683
 _vm_unmap_aliases+0x453/0x4e0 mm/vmalloc.c:2107
 vm_remove_mappings mm/vmalloc.c:2584 [inline]
 __vunmap+0x72e/0xa20 mm/vmalloc.c:2611
 bpf_jit_binary_free kernel/bpf/core.c:910 [inline]
 bpf_jit_free+0x92/0x180 kernel/bpf/core.c:923
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2307
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2454
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
NMI backtrace for cpu 0
CPU: 0 PID: 709 Comm: kworker/u4:9 Not tainted 5.15.119-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_dump_cpu_stacks+0x223/0x390 kernel/rcu/tree_stall.h:343
 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:711 [inline]
 rcu_pending kernel/rcu/tree.c:3911 [inline]
 rcu_sched_clock_irq+0xf26/0x1770 kernel/rcu/tree.c:2606
 update_process_times+0x196/0x200 kernel/time/timer.c:1788
 tick_sched_handle kernel/time/tick-sched.c:237 [inline]
 tick_sched_timer+0x22d/0x3c0 kernel/time/tick-sched.c:1441
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
 __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__raw_write_unlock_irq include/linux/rwlock_api_smp.h:268 [inline]
RIP: 0010:_raw_write_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:348
Code: 01 95 f6 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 fe 7f 3d f7 48 89 df e8 36 e4 3e f7 e8 01 60 61 f7 fb bf 01 00 00 00 <e8> 16 10 32 f7 65 8b 05 17 5c dd 75 85 c0 74 02 5b c3 e8 24 73 db
RSP: 0018:ffffc900025c7dd0 EFLAGS: 00000286
RAX: 4f8c3e2eb1dc2900 RBX: ffffffff8c60a040 RCX: ffffffff913c4003
RDX: dffffc0000000000 RSI: ffffffff8a8afc60 RDI: 0000000000000001
RBP: ffffc900025c7f10 R08: ffffffff818673d0 R09: fffffbfff1bc79fe
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: 1ffff1100f1db0ab R14: ffff888022a48680 R15: ffffc900025c7e60
 exit_notify kernel/exit.c:742 [inline]
 do_exit+0x161c/0x2480 kernel/exit.c:892
 call_usermodehelper_exec_async+0x368/0x370 kernel/umh.c:125
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/07/01 16:55 linux-5.15.y 4af60700a60c bfc47836 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in call_usermodehelper_exec_async
* Struck through repros no longer work on HEAD.