syzbot


INFO: rcu detected stall in try_check_zero (3)

Status: closed as invalid on 2022/02/08 10:10
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 322d, last: 319d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in try_check_zero 66 933d 1376d 0/24 auto-closed as invalid on 2020/09/05 16:29
upstream INFO: rcu detected stall in try_check_zero (2) 1 803d 803d 0/24 auto-closed as invalid on 2020/12/15 14:13

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...0: (1 GPs behind) idle=d8d/1/0x4000000000000000 softirq=44550/44551 fqs=5244 
	(detected by 0, t=10502 jiffies, g=72117, q=776)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4495 Comm: kworker/1:8 Not tainted 5.16.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: rcu_gp process_srcu
RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:330 [inline]
RIP: 0010:rcu_is_watching+0xd/0xa0 kernel/rcu/tree.c:1128
Code: 45 b2 8c 4c 89 e6 e8 02 1c d6 02 e9 2a ff ff ff e8 08 49 a4 08 0f 1f 84 00 00 00 00 00 41 57 41 56 53 65 83 05 bb 7e 93 7e 01 <e8> 8e 5b a4 08 89 c3 83 f8 08 73 71 49 bf 00 00 00 00 00 fc ff df
RSP: 0018:ffffc90000dc0a60 EFLAGS: 00000006
RAX: 0000000000000001 RBX: 1ffff920001b8150 RCX: ffff888023e65700
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e004ba8
RBP: ffffc90000dc0b10 R08: dffffc0000000000 R09: fffffbfff1c00976
R10: fffffbfff1c00976 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff920001b8174 R14: dffffc0000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff7851aa904 CR3: 0000000081c7a000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_read_lock_held_common kernel/rcu/update.c:108 [inline]
 rcu_read_lock_sched_held+0x6b/0x130 kernel/rcu/update.c:123
 trace_lock_release+0x4f/0x150 include/trace/events/lock.h:58
 lock_release+0x82/0x810 kernel/locking/lockdep.c:5650
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
 _raw_spin_unlock_irqrestore+0x75/0x130 kernel/locking/spinlock.c:194
 debug_hrtimer_deactivate kernel/time/hrtimer.c:425 [inline]
 debug_deactivate kernel/time/hrtimer.c:481 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1653 [inline]
 __hrtimer_run_queues+0x2f9/0xa60 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3b3/0x1040 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0xf9/0x270 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20
RIP: 0010:rdtsc_ordered arch/x86/include/asm/msr.h:234 [inline]
RIP: 0010:delay_tsc+0x7d/0xe0 arch/x86/lib/delay.c:72
Code: 39 f5 73 75 66 0f 1f 84 00 00 00 00 00 a8 01 75 45 f3 90 bf 01 00 00 00 e8 b0 c5 0e fd e8 cb 0c c8 05 41 39 c7 75 36 0f 01 f9 <66> 90 48 89 d5 48 c1 e5 20 48 09 c5 48 29 dd bf 01 00 00 00 e8 ba
RSP: 0018:ffffc90004037ad0 EFLAGS: 00000246
RAX: 000000009ea46960 RBX: 000001419ea4444a RCX: 0000000000000001
RDX: 0000000000000141 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 000000000000248e R08: ffffffff8445d98a R09: ffffffff8445d8e0
R10: 0000000000000009 R11: ffff888023e65700 R12: 0000000000012208
R13: 0000000000000001 R14: 0000000000002af9 R15: 0000000000000001
 try_check_zero+0x35b/0x3d0 kernel/rcu/srcutree.c:702
 srcu_advance_state kernel/rcu/srcutree.c:1227 [inline]
 process_srcu+0x1a7/0xc60 kernel/rcu/srcutree.c:1325
 process_one_work+0x850/0x1130 kernel/workqueue.c:2307
 worker_thread+0xab1/0x1300 kernel/workqueue.c:2454
 kthread+0x468/0x490 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30
 </TASK>
----------------
Code disassembly (best guess):
   0:	45 b2 8c             	rex.RB mov $0x8c,%r10b
   3:	4c 89 e6             	mov    %r12,%rsi
   6:	e8 02 1c d6 02       	callq  0x2d61c0d
   b:	e9 2a ff ff ff       	jmpq   0xffffff3a
  10:	e8 08 49 a4 08       	callq  0x8a4491d
  15:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
  1c:	00
  1d:	41 57                	push   %r15
  1f:	41 56                	push   %r14
  21:	53                   	push   %rbx
  22:	65 83 05 bb 7e 93 7e 	addl   $0x1,%gs:0x7e937ebb(%rip)        # 0x7e937ee5
  29:	01
* 2a:	e8 8e 5b a4 08       	callq  0x8a45bbd <-- trapping instruction
  2f:	89 c3                	mov    %eax,%ebx
  31:	83 f8 08             	cmp    $0x8,%eax
  34:	73 71                	jae    0xa7
  36:	49 bf 00 00 00 00 00 	movabs $0xdffffc0000000000,%r15
  3d:	fc ff df

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-smack-root 2022/01/13 01:48 upstream f079ab01b560 44d1319a .config log report info INFO: rcu detected stall in try_check_zero
ci-upstream-kasan-gce-root 2022/01/10 00:20 upstream e900deb24820 2ca0d385 .config log report info INFO: rcu detected stall in try_check_zero
* Struck through repros no longer work on HEAD.