syzbot


INFO: rcu detected stall in do_divide_error

Status: closed as dup on 2018/09/11 09:35
Subsystems: kvm
[Documentation on labels]
Reported-by: syzbot+f552ab5e1b88aec5fec5@syzkaller.appspotmail.com
First crash: 2056d, last: 2056d
Duplicate of
Title Repro Cause bisect Fix bisect Count Last Reported
INFO: rcu detected stall in kvm_vcpu_ioctl mm C error unreliable 251 876d 2054d

Sample crash report:
ISOFS: Unable to identify CD-ROM format.
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=30245, q=238)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294970582-4294960079), jiffies_till_next_fqs=1, root ->qsmask 0x0
syz-executor6   R  running task    21680 14040   5565 0x00000000
Call Trace:
 <IRQ>
 sched_show_task.cold.83+0x2b6/0x30a kernel/sched/core.c:5296
 print_other_cpu_stall.cold.79+0xa83/0xba5 kernel/rcu/tree.c:1430
 check_cpu_stall kernel/rcu/tree.c:1557 [inline]
 __rcu_pending kernel/rcu/tree.c:3276 [inline]
 rcu_pending kernel/rcu/tree.c:3319 [inline]
 rcu_check_callbacks+0xafc/0x1990 kernel/rcu/tree.c:2665
 update_process_times+0x2d/0x70 kernel/time/timer.c:1636
 tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164
 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274
 __run_hrtimer kernel/time/hrtimer.c:1398 [inline]
 __hrtimer_run_queues+0x41c/0x10d0 kernel/time/hrtimer.c:1460
 hrtimer_interrupt+0x313/0x780 kernel/time/hrtimer.c:1518
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1029 [inline]
 smp_apic_timer_interrupt+0x1a1/0x760 arch/x86/kernel/apic/apic.c:1054
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:864
 </IRQ>
RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:798 [inline]
RIP: 0010:cond_local_irq_enable arch/x86/kernel/traps.c:80 [inline]
RIP: 0010:do_error_trap+0x270/0x4d0 arch/x86/kernel/traps.c:301
Code: 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 4f 02 00 00 48 83 3d 55 a1 27 08 00 0f 84 46 01 00 00 fb 66 0f 1f 44 00 00 <e9> b8 fe ff ff 31 c0 41 b8 01 00 00 00 48 ba 00 00 00 00 00 fc ff
RSP: 0018:ffff8801b513e8e8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: ffff8801b513ea38 RCX: 1ffff10036bf8db4
RDX: 1ffffffff12a4537 RSI: ffff8801b5fc6da8 RDI: ffffffff895229b8
RBP: ffff8801b513ea18 R08: ffff8801b5fc6da0 R09: 0000000000000006
R10: 0000000000000000 R11: ffff8801b5fc6500 R12: 0000000000000000
R13: ffff8801b513e9f0 R14: 0000000000000008 R15: 1ffff10036a27d22
 do_divide_error+0x18/0x20 arch/x86/kernel/traps.c:314
 divide_error+0x14/0x20 arch/x86/entry/entry_64.S:990
RIP: 0010:em_idiv_ex+0x0/0x8
Code: 00 00 48 f7 e9 c3 0f 1f 40 00 f6 f1 c3 0f 1f 44 00 00 66 f7 f1 c3 0f 1f 40 00 f7 f1 c3 0f 1f 44 00 00 48 f7 f1 c3 0f 1f 40 00 <f6> f9 c3 0f 1f 44 00 00 66 f7 f9 c3 0f 1f 40 00 f7 f9 c3 0f 1f 44
RSP: 0018:ffff8801b513eae0 EFLAGS: 00010202
RAX: 0000000000000000 RBX: ffff8801d2494fe0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81147628 RDI: 0000000000000200
RBP: ffff8801b513eb18 R08: ffff8801b5fc6500 R09: 1ffffffff12b43cd
R10: ffffed003b5c4732 R11: ffff8801dae23993 R12: 0000000000000000
R13: ffffffff81147628 R14: 0000000000000001 R15: ffffffff81147628
 x86_emulate_insn+0x1efd/0x5020 arch/x86/kvm/emulate.c:5587
 x86_emulate_instruction+0xd45/0x1fc0 arch/x86/kvm/x86.c:6224
 kvm_mmu_page_fault+0x396/0x1b30 arch/x86/kvm/mmu.c:5280
 handle_ept_violation+0x29e/0x6a0 arch/x86/kvm/vmx.c:7679
 vmx_handle_exit+0x2f7/0x17e0 arch/x86/kvm/vmx.c:10115
 vcpu_enter_guest+0x14a9/0x62e0 arch/x86/kvm/x86.c:7648
 vcpu_run arch/x86/kvm/x86.c:7711 [inline]
 kvm_arch_vcpu_ioctl_run+0x375/0x16e0 arch/x86/kvm/x86.c:7888
 kvm_vcpu_ioctl+0x72b/0x1150 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2590
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
 __do_sys_ioctl fs/ioctl.c:709 [inline]
 __se_sys_ioctl fs/ioctl.c:707 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457099
Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f9ce5ec5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f9ce5ec66d4 RCX: 0000000000457099
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000006
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004cf730 R14: 00000000004c59b9 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10617 jiffies! g30245 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    23064    10      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2825 [inline]
 __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473
 schedule+0xfe/0x460 kernel/sched/core.c:3517
 schedule_timeout+0x140/0x260 kernel/time/timer.c:1804
 rcu_gp_kthread+0x9d9/0x2310 kernel/rcu/tree.c:2194
 kthread+0x35a/0x420 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
device bridge_slave_1 left promiscuous mode
bridge0: port 2(bridge_slave_1) entered disabled state
device bridge_slave_0 left promiscuous mode
bridge0: port 1(bridge_slave_0) entered disabled state
team0 (unregistering): Port device team_slave_1 removed
team0 (unregistering): Port device team_slave_0 removed
bond0 (unregistering): Releasing backup interface bond_slave_1
bond0 (unregistering): Releasing backup interface bond_slave_0
bond0 (unregistering): Released all slaves

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/09/09 04:13 upstream f8f65382c98a 6b5120a4 .config console log report ci-upstream-kasan-gce-selinux-root
2018/09/08 16:01 upstream d7b686ebf704 6b5120a4 .config console log report ci-upstream-kasan-gce-selinux-root
* Struck through repros no longer work on HEAD.