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BUG: KASAN: slab-out-of-bounds in perf_exclude_event+0x18b/0x1a0 kernel/events/core.c:7895
Read of size 8 at addr ffff880186dffde0 by task syz-executor3/2696

CPU: 0 PID: 2696 Comm: syz-executor3 Not tainted 4.19.0-rc6-next-20181004+ #87
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d3/0x2c4 lib/dump_stack.c:113
 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 perf_exclude_event+0x18b/0x1a0 kernel/events/core.c:7895
 perf_swevent_hrtimer+0x28f/0x510 kernel/events/core.c:9122
 __run_hrtimer kernel/time/hrtimer.c:1398 [inline]
 __hrtimer_run_queues+0x412/0x10c0 kernel/time/hrtimer.c:1460
 hrtimer_interrupt+0x313/0x780 kernel/time/hrtimer.c:1518
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1034 [inline]
 smp_apic_timer_interrupt+0x1a1/0x750 arch/x86/kernel/apic/apic.c:1059
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:804
 </IRQ>

Allocated by task 2525:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
 __do_kmalloc_node mm/slab.c:3684 [inline]
 __kmalloc_node+0x50/0x70 mm/slab.c:3691
 kmalloc_node include/linux/slab.h:589 [inline]
 kvmalloc_node+0xb9/0xf0 mm/util.c:423
 kvmalloc include/linux/mm.h:577 [inline]
 kvzalloc include/linux/mm.h:585 [inline]
 __kvm_set_memory_region+0x114a/0x2c60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1020
 kvm_set_memory_region+0x2e/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1082
 kvm_vm_ioctl_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1094 [inline]
 kvm_vm_ioctl+0x652/0x1d60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2986
 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

Freed by task 2525:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kfree+0xcf/0x230 mm/slab.c:3817
 kvfree+0x61/0x70 mm/util.c:452
 __kvm_set_memory_region+0x1b19/0x2c60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1064
 kvm_set_memory_region+0x2e/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1082
 kvm_vm_ioctl_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1094 [inline]
 kvm_vm_ioctl+0x652/0x1d60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2986
 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

The buggy address belongs to the object at ffff880186de2e00
 which belongs to the cache kmalloc-64k of size 65536
The buggy address is located 53216 bytes to the right of
 65536-byte region [ffff880186de2e00, ffff880186df2e00)
The buggy address belongs to the page:
page:ffffea00061b7800 count:1 mapcount:0 mapping:ffff8801da802500 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000010200(slab|head)
raw: 02fffc0000010200 ffffea0006de4808 ffffea00066f4008 ffff8801da802500
raw: 0000000000000000 ffff880186de2e00 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff880186dffc80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff880186dffd00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff880186dffd80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                       ^
 ffff880186dffe00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff880186dffe80: fc fc f1 f1 f1 f1 00 f2 f2 f2 f2 f2 f2 f2 00 f2
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