syzbot


INFO: rcu detected stall in sys_wait4 (4)

Status: fixed on 2024/07/12 01:55
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+6969434de600a6ba9f07@syzkaller.appspotmail.com
Fix commit: fb66df20a720 net/sched: taprio: extend minimum interval restriction to entire cycle too
First crash: 244d, last: 207d
Cause bisection: introduced by (bisect log) :
commit 51ea51b18904cd1a0fb244ce41dfd903c2ada628
Author: Shuming Fan <shumingf@realtek.com>
Date: Fri Dec 23 05:58:46 2022 +0000

  ASoC: rt711-sdca: add jack detection mode for JD2 100K

Crash: INFO: rcu detected stall in do_idle (log)
Repro: C syz .config
  
Fix bisection: fixed by (bisect log) :
commit fb66df20a7201e60f2b13d7f95d031b31a8831d3
Author: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: Mon May 27 15:39:55 2024 +0000

  net/sched: taprio: extend minimum interval restriction to entire cycle too

  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [kernel?] INFO: rcu detected stall in sys_wait4 (4) 1 (4) 2024/07/11 12:28
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_wait4 (3) kernel 1 470d 470d 0/28 auto-obsoleted due to no activity on 2023/11/24 01:26
upstream INFO: rcu detected stall in sys_wait4 (2) kernel 1 978d 978d 0/28 auto-closed as invalid on 2022/07/03 11:21
upstream INFO: rcu detected stall in sys_wait4 kernel 1 1609d 1609d 0/28 auto-closed as invalid on 2020/10/10 08:00
linux-5.15 INFO: rcu detected stall in sys_wait4 1 177d 177d 0/3 auto-obsoleted due to no activity on 2024/09/21 03:35
linux-6.1 INFO: rcu detected stall in sys_wait4 1 606d 606d 0/3 auto-obsoleted due to no activity on 2023/08/09 13:38
Last patch testing requests (2)
Created Duration User Patch Repo Result
2024/07/07 00:21 1h09m retest repro upstream OK log
2024/04/26 15:40 52m retest repro upstream report log

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 ticks this GP) idle=e314/1/0x4000000000000000 softirq=5879/5879 fqs=0
rcu: 	(detected by 1, t=10505 jiffies, g=6797, q=86 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5083 Comm: syz-executor176 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:__raw_spin_lock_irq include/linux/spinlock_api_smp.h:120 [inline]
RIP: 0010:_raw_spin_lock_irq+0xd7/0x120 kernel/locking/spinlock.c:170
Code: bf 01 00 00 00 e8 69 e1 e5 f5 49 8d 7c 24 18 31 f6 31 d2 31 c9 41 b8 01 00 00 00 45 31 c9 ff 75 08 e8 1d 90 f2 f5 48 83 c4 08 <4c> 89 e7 e8 c1 f0 f3 f5 48 c7 04 24 0e 36 e0 45 4b c7 04 2f 00 00
RSP: 0018:ffffc90000007cc0 EFLAGS: 00000096
RAX: c05eb13d16091700 RBX: 1ffff92000000f9c RCX: 0000000000000001
RDX: dffffc0000000000 RSI: ffffffff8baad360 RDI: ffffffff8bfed300
RBP: ffffc90000007d50 R08: ffffffff92ce550f R09: 1ffffffff259caa1
R10: dffffc0000000000 R11: fffffbfff259caa2 R12: ffff8880b942c8c0
R13: 1ffff92000000f98 R14: ffffc90000007ce0 R15: dffffc0000000000
FS:  000055556b411380(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556b411ca8 CR3: 000000002dd76000 CR4: 0000000000350ef0
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __run_hrtimer kernel/time/hrtimer.c:1696 [inline]
 __hrtimer_run_queues+0x65a/0xd00 kernel/time/hrtimer.c:1756
 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1818
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline]
 __sysvec_apic_timer_interrupt+0x109/0x3a0 arch/x86/kernel/apic/apic.c:1049
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194
Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 4e 39 79 f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> f3 e0 e5 f5 65 8b 05 44 c5 84 74 85 c0 74 43 48 c7 04 24 0e 36
RSP: 0018:ffffc900042f7b40 EFLAGS: 00000206
RAX: c05eb13d16091700 RBX: 1ffff9200085ef6c RCX: ffffffff944dd603
RDX: dffffc0000000000 RSI: ffffffff8baac1e0 RDI: 0000000000000001
RBP: ffffc900042f7bd8 R08: ffffffff8f873a6f R09: 1ffffffff1f0e74d
R10: dffffc0000000000 R11: fffffbfff1f0e74e R12: dffffc0000000000
R13: 1ffff9200085ef68 R14: ffffc900042f7b60 R15: 0000000000000246
 do_wait+0x16e/0x540 kernel/exit.c:1627
 kernel_wait4+0x2a7/0x3e0 kernel/exit.c:1790
 __do_sys_wait4 kernel/exit.c:1818 [inline]
 __se_sys_wait4 kernel/exit.c:1814 [inline]
 __x64_sys_wait4+0x134/0x1e0 kernel/exit.c:1814
 do_syscall_64+0xfd/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f6df57cd893
Code: fe ff e9 41 ff ff ff 31 c9 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 80 3d 11 f8 07 00 00 49 89 ca 74 14 b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5d c3 0f 1f 40 00 48 83 ec 28 89 54 24 14 48
RSP: 002b:00007ffe2065f398 EFLAGS: 00000202 ORIG_RAX: 000000000000003d
RAX: ffffffffffffffda RBX: 000000000000000b RCX: 00007f6df57cd893
RDX: 0000000040000001 RSI: 00007ffe2065f3bc RDI: 00000000ffffffff
RBP: 00000000000f4240 R08: 0000000000000010 R09: 00007f6df578b0b0
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffe2065f3f0
R13: 00000000000306b6 R14: 00007ffe2065f3bc R15: 0000000000000003
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.866 msecs
rcu: rcu_preempt kthread timer wakeup didn't happen for 10504 jiffies! g6797 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=7994
rcu: rcu_preempt kthread starved for 10505 jiffies! g6797 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
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:25400 pid:16    tgid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0x17d3/0x4a20 kernel/sched/core.c:6736
 __schedule_loop kernel/sched/core.c:6813 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6828
 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2572
 rcu_gp_fqs_loop+0x2df/0x1370 kernel/rcu/tree.c:1663
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1862
 kthread+0x2f2/0x390 kernel/kthread.c:388
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/07 18:04 upstream fe46a7dd189e ca620dd8 .config console log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_wait4
2024/05/14 15:02 net-next 5c1672705a1a fdb4c10c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in sys_wait4
* Struck through repros no longer work on HEAD.