syzbot

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=8ee/1/0x4000000000000000 softirq=17392/17392 fqs=0 
	(t=10500 jiffies g=21969 q=85)
rcu: rcu_preempt kthread starved for 10500 jiffies! g21969 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:29080 pid:   10 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:3778 [inline]
 __schedule+0x8e5/0x21e0 kernel/sched/core.c:4527
 schedule+0xd0/0x2a0 kernel/sched/core.c:4602
 schedule_timeout+0x148/0x250 kernel/time/timer.c:1879
 rcu_gp_fqs_loop kernel/rcu/tree.c:1888 [inline]
 rcu_gp_kthread+0xae5/0x1b50 kernel/rcu/tree.c:2058
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 11042 Comm: kworker/0:5 Not tainted 5.9.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: rcu_gp process_srcu
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:91 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:108 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:134 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:165 [inline]
RIP: 0010:check_memory_region_inline mm/kasan/generic.c:183 [inline]
RIP: 0010:check_memory_region+0xdb/0x180 mm/kasan/generic.c:192
Code: 80 38 00 74 f2 48 89 c2 b8 01 00 00 00 48 85 d2 75 56 5b 5d 41 5c c3 48 85 d2 74 5e 48 01 ea eb 09 48 83 c0 01 48 39 d0 74 50 <80> 38 00 74 f2 eb d4 41 bc 08 00 00 00 48 89 ea 45 29 dc 4d 8d 1c
RSP: 0018:ffffc90000007678 EFLAGS: 00000086
RAX: fffffbfff15646c9 RBX: fffffbfff15646ca RCX: ffffffff815a6c5b
RDX: fffffbfff15646ca RSI: 0000000000000008 RDI: ffffffff8ab23648
RBP: fffffbfff15646c9 R08: 0000000000000000 R09: ffffffff8ab2364f
R10: fffffbfff15646c9 R11: 0000000000000160 R12: 0000000000000002
R13: ffffffff89be8488 R14: 0000000000000000 R15: ffff88809443c380
FS:  0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000030c22000 CR3: 0000000009a8d000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 instrument_atomic_read include/linux/instrumented.h:56 [inline]
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:110 [inline]
 cpumask_test_cpu include/linux/cpumask.h:367 [inline]
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0x1ab/0xad0 kernel/locking/lockdep.c:5004
 seqcount_lockdep_reader_access include/linux/seqlock.h:102 [inline]
 read_seqcount_t_begin.constprop.0+0xae/0x1f0 include/linux/seqlock.h:311
 ktime_get_with_offset+0x7a/0x1a0 kernel/time/timekeeping.c:803
 ktime_get_real include/linux/timekeeping.h:79 [inline]
 __net_timestamp include/linux/skbuff.h:3711 [inline]
 netif_rx_internal+0x1fd/0x6a0 net/core/dev.c:4767
 netif_rx+0x82/0x5d0 net/core/dev.c:4819
 veth_forward_skb drivers/net/veth.c:280 [inline]
 veth_xmit+0x5d4/0x870 drivers/net/veth.c:309
 __netdev_start_xmit include/linux/netdevice.h:4634 [inline]
 netdev_start_xmit include/linux/netdevice.h:4648 [inline]
 xmit_one net/core/dev.c:3561 [inline]
 dev_hard_start_xmit+0x193/0x950 net/core/dev.c:3577
 __dev_queue_xmit+0x2091/0x2d60 net/core/dev.c:4136
 hsr_xmit net/hsr/hsr_forward.c:333 [inline]
 hsr_forward_do net/hsr/hsr_forward.c:409 [inline]
 hsr_forward_skb+0xab1/0x1766 net/hsr/hsr_forward.c:541
 send_hsr_supervision_frame+0x5fc/0xb40 net/hsr/hsr_device.c:338
 hsr_announce+0x122/0x320 net/hsr/hsr_device.c:404
 call_timer_fn+0x1ac/0x760 kernel/time/timer.c:1413
 expire_timers kernel/time/timer.c:1458 [inline]
 __run_timers.part.0+0x67c/0xaa0 kernel/time/timer.c:1755
 __run_timers kernel/time/timer.c:1736 [inline]
 run_timer_softirq+0xae/0x1a0 kernel/time/timer.c:1768
 __do_softirq+0x2de/0xa24 kernel/softirq.c:298
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 do_softirq_own_stack+0x9d/0xd0 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:393 [inline]
 __irq_exit_rcu kernel/softirq.c:423 [inline]
 irq_exit_rcu+0x1f3/0x230 kernel/softirq.c:435
 sysvec_apic_timer_interrupt+0x51/0xf0 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581
RIP: 0010:preempt_schedule_irq+0xa6/0x150 kernel/sched/core.c:4785
Code: 00 00 e8 4d 81 5a f9 e8 f8 bf 84 f9 4c 89 e8 48 c1 e8 03 80 3c 18 00 75 7a 48 83 3d 7b f5 c0 01 00 74 6c fb 66 0f 1f 44 00 00 <bf> 01 00 00 00 e8 30 cf ff ff 48 c7 c0 d0 3b b6 89 48 c1 e8 03 80
RSP: 0018:ffffc9001582fb38 EFLAGS: 00000286
RAX: 1ffffffff136c77b RBX: dffffc0000000000 RCX: 0000000000000006
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff87f54648
RBP: ffffed1012887870 R08: 0000000000000001 R09: ffffffff8c5f39ff
R10: fffffbfff18be73f R11: 0000000000000000 R12: ffff88809443c380
R13: ffffffff89b63bd8 R14: 0000000000000000 R15: 0000000000000000
 irqentry_exit_cond_resched kernel/entry/common.c:333 [inline]
 irqentry_exit_cond_resched kernel/entry/common.c:325 [inline]
 irqentry_exit+0x65/0x90 kernel/entry/common.c:363
 asm_sysvec_reschedule_ipi+0x12/0x20 arch/x86/include/asm/idtentry.h:586
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:770 [inline]
RIP: 0010:lock_acquire+0x27b/0xad0 kernel/locking/lockdep.c:5008
Code: 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 f8 06 00 00 48 83 3d aa ce 5b 08 00 0f 84 a6 05 00 00 48 8b 7c 24 08 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 03 44 24 10 48 c7
RSP: 0018:ffffc9001582fc10 EFLAGS: 00000286
RAX: 1ffffffff136c779 RBX: ffff88809443c380 RCX: ffffffff815a14fb
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: 0000000000000286
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8c5f39ff
R10: fffffbfff18be73f R11: 0000000000000000 R12: 0000000000000000
R13: ffff8880aa073538 R14: 0000000000000000 R15: ffff88809443c380
 process_one_work+0x88c/0x1670 kernel/workqueue.c:2244
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
NMI backtrace for cpu 1
CPU: 1 PID: 6545 Comm: kworker/1:3 Not tainted 5.9.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events free_work
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x18f/0x20d lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x194/0x1cf kernel/rcu/tree_stall.h:318
 print_cpu_stall kernel/rcu/tree_stall.h:551 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:625 [inline]
 rcu_pending kernel/rcu/tree.c:3637 [inline]
 rcu_sched_clock_irq.cold+0x5b3/0xccd kernel/rcu/tree.c:2519
 update_process_times+0x25/0xa0 kernel/time/timer.c:1710
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176
 tick_sched_timer+0x1d1/0x2a0 kernel/time/tick-sched.c:1328
 __run_hrtimer kernel/time/hrtimer.c:1524 [inline]
 __hrtimer_run_queues+0x1d5/0xfc0 kernel/time/hrtimer.c:1588
 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1650
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline]
 __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1097
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 sysvec_apic_timer_interrupt+0xb2/0xf0 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581
RIP: 0010:write_comp_data+0x2f/0x80 kernel/kcov.c:218
Code: 05 26 c4 8d 7e 65 48 8b 34 25 c0 fe 01 00 a9 00 01 ff 00 74 0f f6 c4 01 74 59 8b 86 24 14 00 00 85 c0 74 4f 8b 86 00 14 00 00 <83> f8 03 75 44 48 8b 86 08 14 00 00 8b b6 04 14 00 00 4c 8b 00 48
RSP: 0018:ffffc90009fa7998 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff920013f4f38 RCX: ffffffff81693505
RDX: 0000000000000001 RSI: ffff88809e37a4c0 RDI: 0000000000000005
RBP: ffffc90009fa7a70 R08: 0000000000000001 R09: ffff8880ae636dc7
R10: 0000000000000000 R11: 0000000000000160 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000040
 csd_lock_wait kernel/smp.c:108 [inline]
 smp_call_function_single+0x1a5/0x4f0 kernel/smp.c:382
 smp_call_function_many_cond+0x1a4/0x990 kernel/smp.c:518
 smp_call_function_many kernel/smp.c:577 [inline]
 smp_call_function kernel/smp.c:599 [inline]
 on_each_cpu+0x4a/0x240 kernel/smp.c:698
 flush_tlb_kernel_range+0x197/0x250 arch/x86/mm/tlb.c:984
 __purge_vmap_area_lazy+0x7f7/0x1b70 mm/vmalloc.c:1373
 try_purge_vmap_area_lazy mm/vmalloc.c:1392 [inline]
 free_vmap_area_noflush+0x2bc/0x370 mm/vmalloc.c:1428
 free_unmap_vmap_area mm/vmalloc.c:1441 [inline]
 remove_vm_area+0x1ca/0x230 mm/vmalloc.c:2174
 vm_remove_mappings mm/vmalloc.c:2201 [inline]
 __vunmap+0x348/0xac0 mm/vmalloc.c:2263
 free_work+0x58/0x70 mm/vmalloc.c:69
 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294