syzbot


INFO: rcu detected stall in sys_wait4 (2)

Status: auto-closed as invalid on 2022/07/03 11:21
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 246d, last: 246d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_wait4 1 877d 877d 0/24 auto-closed as invalid on 2020/10/10 08:00

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=d5f/1/0x4000000000000000 softirq=178090/178094 fqs=4 
	(detected by 0, t=10502 jiffies, g=262429, q=52)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 31863 Comm: syz-executor.2 Not tainted 5.18.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:check_preemption_disabled+0x3/0x1c0 lib/smp_processor_id.c:13
Code: cc cc cc cc cc cc cc 0f 1f 44 00 00 48 c7 c7 20 d7 f6 8a 48 c7 c6 60 d7 f6 8a eb 0b 66 2e 0f 1f 84 00 00 00 00 00 90 55 41 57 <41> 56 41 55 41 54 53 48 83 ec 10 49 89 f6 49 89 ff 65 48 8b 04 25
RSP: 0018:ffffc900001e09c0 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000080010002
RDX: 0000000000000000 RSI: ffffffff8a8f5c60 RDI: ffffffff8af6d7a0
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1c426fe
R10: fffffbfff1c426fe R11: 0000000000000000 R12: 0000000000000046
R13: ffff888044e43a00 R14: 00000000ffffffff R15: ffffffff8cd1ccc0
FS:  0000555556189400(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff56a98c18 CR3: 000000007c27f000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lockdep_recursion_finish kernel/locking/lockdep.c:436 [inline]
 lock_is_held_type+0x10a/0x190 kernel/locking/lockdep.c:5685
 lock_is_held include/linux/lockdep.h:283 [inline]
 rcu_read_lock_sched_held+0x89/0x130 kernel/rcu/update.c:125
 trace_lock_acquire+0x59/0x190 include/trace/events/lock.h:13
 lock_acquire+0xa5/0x4d0 kernel/locking/lockdep.c:5612
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:268
 rcu_read_lock include/linux/rcupdate.h:694 [inline]
 advance_sched+0x6e7/0x930 net/sched/sch_taprio.c:767
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x50b/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:lock_acquire+0x21f/0x4d0 kernel/locking/lockdep.c:5645
Code: 08 4c 89 f7 e8 02 b8 70 00 f6 84 24 81 00 00 00 02 0f 85 13 02 00 00 41 f7 c4 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 04 2f 00 00 00 00 43 c7 44 2f 09 00 00 00 00 43 c7 44 2f 11
RSP: 0018:ffffc90008df7a80 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff920011bef60 RCX: ffff888044e44458
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90008df7bd8 R08: dffffc0000000000 R09: fffffbfff1f86d83
R10: fffffbfff1f86d83 R11: 0000000000000000 R12: 0000000000000246
R13: 1ffff920011bef58 R14: ffffc90008df7b00 R15: dffffc0000000000
 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
 _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:228
 do_wait+0x224/0x9d0 kernel/exit.c:1508
 kernel_wait4+0x2a3/0x3c0 kernel/exit.c:1681
 __do_sys_wait4 kernel/exit.c:1709 [inline]
 __se_sys_wait4 kernel/exit.c:1705 [inline]
 __x64_sys_wait4+0x130/0x1e0 kernel/exit.c:1705
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x50 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f9a6b6874e7
Code: 89 7c 24 10 48 89 4c 24 18 e8 35 50 02 00 4c 8b 54 24 18 8b 54 24 14 41 89 c0 48 8b 74 24 08 8b 7c 24 10 b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 89 44 24 10 e8 65 50 02 00 8b 44
RSP: 002b:00007ffc0da914e0 EFLAGS: 00000293 ORIG_RAX: 000000000000003d
RAX: ffffffffffffffda RBX: 0000000000000395 RCX: 00007f9a6b6874e7
RDX: 0000000040000001 RSI: 00007ffc0da9156c RDI: 00000000ffffffff
RBP: 00007ffc0da9156c R08: 0000000000000000 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032
R13: 00000000001e6429 R14: 0000000000000000 R15: 00007ffc0da915d0
 </TASK>
rcu: rcu_preempt kthread starved for 10494 jiffies! g262429 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:26480 pid:   16 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5073 [inline]
 __schedule+0x937/0x1090 kernel/sched/core.c:6382
 schedule+0xeb/0x1b0 kernel/sched/core.c:6454
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1881
 rcu_gp_fqs_loop+0x1fd/0x770 kernel/rcu/tree.c:1971
 rcu_gp_kthread+0xa5/0x350 kernel/rcu/tree.c:2144
 kthread+0x2a3/0x2d0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 7816 Comm: kworker/u4:4 Not tainted 5.18.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound toggle_allocation_gate
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x45f/0x490 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_check_gp_kthread_starvation+0x1ff/0x270 kernel/rcu/tree_stall.h:490
 print_other_cpu_stall kernel/rcu/tree_stall.h:595 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:741 [inline]
 rcu_pending kernel/rcu/tree.c:3923 [inline]
 rcu_sched_clock_irq+0x24e1/0x2cf0 kernel/rcu/tree.c:2625
 update_process_times+0x197/0x200 kernel/time/timer.c:1785
 tick_sched_handle kernel/time/tick-sched.c:243 [inline]
 tick_sched_timer+0x376/0x540 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4cb/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:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_many_cond+0xc22/0xe10 kernel/smp.c:969
Code: 83 e6 01 31 ff e8 1e c3 0b 00 41 83 e7 01 49 bf 00 00 00 00 00 fc ff df 75 0e e8 f9 be 0b 00 eb 4c 0f 1f 80 00 00 00 00 f3 90 <42> 0f b6 04 3b 84 c0 75 11 41 f7 45 00 01 00 00 00 74 2b e8 d6 be
RSP: 0018:ffffc90015bdf820 EFLAGS: 00000293
RAX: ffffffff817a386a RBX: 1ffff11017367fc5 RCX: ffff88801bf39d00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90015bdf960 R08: ffffffff817a3832 R09: ffffffff8457dcc0
R10: 0000000000000009 R11: ffff88801bf39d00 R12: 0000000000000001
R13: ffff8880b9b3fe28 R14: ffff8880b9a3ac80 R15: dffffc0000000000
 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1135
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:1184 [inline]
 text_poke_bp_batch+0x309/0x920 arch/x86/kernel/alternative.c:1372
 text_poke_flush arch/x86/kernel/alternative.c:1542 [inline]
 text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1549
 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x12d/0x250 kernel/jump_label.c:177
 static_key_enable+0x16/0x20 kernel/jump_label.c:190
 toggle_allocation_gate+0xbf/0x460 mm/kfence/core.c:785
 process_one_work+0x83c/0x11a0 kernel/workqueue.c:2289
 worker_thread+0xa6c/0x1290 kernel/workqueue.c:2436
 kthread+0x2a3/0x2d0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30
 </TASK>
----------------
Code disassembly (best guess):
   0:	cc                   	int3
   1:	cc                   	int3
   2:	cc                   	int3
   3:	cc                   	int3
   4:	cc                   	int3
   5:	cc                   	int3
   6:	cc                   	int3
   7:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
   c:	48 c7 c7 20 d7 f6 8a 	mov    $0xffffffff8af6d720,%rdi
  13:	48 c7 c6 60 d7 f6 8a 	mov    $0xffffffff8af6d760,%rsi
  1a:	eb 0b                	jmp    0x27
  1c:	66 2e 0f 1f 84 00 00 	nopw   %cs:0x0(%rax,%rax,1)
  23:	00 00 00
  26:	90                   	nop
  27:	55                   	push   %rbp
  28:	41 57                	push   %r15
* 2a:	41 56                	push   %r14 <-- trapping instruction
  2c:	41 55                	push   %r13
  2e:	41 54                	push   %r12
  30:	53                   	push   %rbx
  31:	48 83 ec 10          	sub    $0x10,%rsp
  35:	49 89 f6             	mov    %rsi,%r14
  38:	49 89 ff             	mov    %rdi,%r15
  3b:	65                   	gs
  3c:	48                   	rex.W
  3d:	8b                   	.byte 0x8b
  3e:	04 25                	add    $0x25,%al

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-smack-root 2022/04/04 11:19 upstream 312310928417 79a2a8fc .config log report info INFO: rcu detected stall in sys_wait4
* Struck through repros no longer work on HEAD.