bisecting fixing commit since 5692097116094a4a7045abcc1dbc172dbdc5657e
building syzkaller on d850e9d08467726cd94b6a9caaf8090c594721ba
testing commit 5692097116094a4a7045abcc1dbc172dbdc5657e with gcc (GCC) 8.1.0
kernel signature: 4cc56dccd191c8b9da8288e702a77bae6c9c831e106a4f240db09f04c96418c3
run #0: crashed: INFO: rcu detected stall in kvm_vcpu_ioctl
run #1: crashed: INFO: rcu detected stall in kvm_vcpu_ioctl
run #2: crashed: INFO: rcu detected stall in kvm_vcpu_ioctl
run #3: crashed: INFO: rcu detected stall in kvm_vcpu_ioctl
run #4: crashed: INFO: rcu detected stall in corrupted
run #5: crashed: INFO: rcu detected stall in kvm_vcpu_ioctl
run #6: crashed: INFO: rcu detected stall in corrupted
run #7: crashed: INFO: rcu detected stall in corrupted
run #8: crashed: INFO: rcu detected stall in kvm_vcpu_ioctl
run #9: crashed: INFO: rcu detected stall in kvm_vcpu_ioctl
testing current HEAD f5d8eef067acee3fda37137f4a08c0d3f6427a8e
testing commit f5d8eef067acee3fda37137f4a08c0d3f6427a8e with gcc (GCC) 8.1.0
kernel signature: c0a7568ab0a28b9f8184ad962c43263573a00524d537437645983032d0f757d2
run #0: crashed: INFO: rcu detected stall in kvm_vcpu_ioctl
run #1: crashed: INFO: rcu detected stall in kvm_vcpu_ioctl
run #2: crashed: INFO: rcu detected stall in kvm_vcpu_ioctl
run #3: crashed: INFO: rcu detected stall in kvm_vcpu_ioctl
run #4: crashed: INFO: rcu detected stall in corrupted
run #5: crashed: INFO: rcu detected stall in kvm_vcpu_ioctl
run #6: crashed: INFO: rcu detected stall in kvm_vcpu_ioctl
run #7: crashed: INFO: rcu detected stall in corrupted
run #8: crashed: INFO: rcu detected stall in kvm_vcpu_ioctl
run #9: crashed: INFO: rcu detected stall in kvm_vcpu_ioctl
revisions tested: 2, total time: 29m4.27405525s (build: 18m35.118754407s, test: 9m19.008155674s)
the crash still happens on HEAD
commit msg: Linux 4.19.154
crash: INFO: rcu detected stall in kvm_vcpu_ioctl
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
IPv6: ADDRCONF(NETDEV_UP): batadv_slave_1: link is not ready
batman_adv: batadv0: Interface activated: batadv_slave_1
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-...!: (3 GPs behind) idle=ee2/1/0x4000000000000002 softirq=9404/9414 fqs=5
rcu: (t=10501 jiffies g=5097 q=597)
rcu: rcu_preempt kthread starved for 10491 jiffies! g5097 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt R running task 29208 10 2 0x80000000
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x78c/0x1c10 kernel/sched/core.c:3517
schedule+0x7f/0x1b0 kernel/sched/core.c:3561
schedule_timeout+0x3ab/0xe00 kernel/time/timer.c:1825
rcu_gp_kthread+0xce6/0x23d0 kernel/rcu/tree.c:2202
kthread+0x347/0x410 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
NMI backtrace for cpu 0
CPU: 0 PID: 7895 Comm: syz-executor.4 Not tainted 4.19.154-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x123/0x177 lib/dump_stack.c:118
nmi_cpu_backtrace.cold.4+0x3e/0x76 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0xe6/0x11a lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
rcu_dump_cpu_stacks+0x175/0x1c2 kernel/rcu/tree.c:1340
print_cpu_stall kernel/rcu/tree.c:1478 [inline]
check_cpu_stall kernel/rcu/tree.c:1550 [inline]
__rcu_pending kernel/rcu/tree.c:3293 [inline]
rcu_pending kernel/rcu/tree.c:3336 [inline]
rcu_check_callbacks.cold.81+0x5cc/0xd67 kernel/rcu/tree.c:2682
update_process_times+0x28/0x90 kernel/time/timer.c:1650
tick_sched_handle+0x77/0x140 kernel/time/tick-sched.c:168
tick_sched_timer+0x37/0xf0 kernel/time/tick-sched.c:1278
__run_hrtimer kernel/time/hrtimer.c:1401 [inline]
__hrtimer_run_queues+0x2f7/0xab0 kernel/time/hrtimer.c:1463
hrtimer_interrupt+0x2df/0x760 kernel/time/hrtimer.c:1521
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline]
smp_apic_timer_interrupt+0x114/0x540 arch/x86/kernel/apic/apic.c:1092
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
RIP: 0010:vcpu_enter_guest+0xba6/0x50a0 arch/x86/kvm/x86.c:7810
Code: 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 00 44 00 00 48 83 3d ef 4a 46 07 00 0f 84 5b 31 00 00 fb 66 0f 1f 44 00 00 01 00 00 00 e8 b0 7e 36 00 65 8b 05 49 3e f6 7e 85 c0 0f 84 3d
RSP: 0018:ffff8880a307f940 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: ffff8880a3288080 RCX: 1ffff11013fead75
RDX: 1ffffffff10a3f4b RSI: ffff88809ff56b88 RDI: ffffffff8851fa58
RBP: ffff8880a307fa80 R08: ffff88809ff56ba8 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88809ff56300
R13: 000000386940819c R14: ffffffe5712d0a39 R15: ffff8880a32880b0
vcpu_run arch/x86/kvm/x86.c:7892 [inline]
kvm_arch_vcpu_ioctl_run+0x2e9/0x1340 arch/x86/kvm/x86.c:8092
kvm_vcpu_ioctl+0x535/0xb60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2823
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0x196/0x10c0 fs/ioctl.c:688
ksys_ioctl+0x62/0x90 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x6e/0xb0 fs/ioctl.c:710
do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c6f9
Code: 2d b6 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 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f0db9a10c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f0db9a116d4 RCX: 000000000045c6f9
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000006
RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000003bf R14: 00000000004c6335 R15: 000000000076bf0c