device nr0
 entered promiscuous mode
==================================================================
BUG: KASAN: slab-out-of-bounds in perf_exclude_event+0x18b/0x1a0 kernel/events/core.c:7895
Read of size 8 at addr ffff880187707fb0 by task syz-executor4/8484

CPU: 0 PID: 8484 Comm: syz-executor4 Not tainted 4.20.0-rc1-next-20181109+ #110
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+0x244/0x39d lib/dump_stack.c:113
 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.8+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:9153
 __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+0x1a1/0x760 arch/x86/kernel/apic/apic.c:1059
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:804
 </IRQ>

Allocated by task 5988:
 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
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc+0x12e/0x730 mm/slab.c:3554
 getname_flags+0xd0/0x590 fs/namei.c:140
 getname fs/namei.c:211 [inline]
 __do_sys_unlink fs/namei.c:4110 [inline]
 __se_sys_unlink fs/namei.c:4108 [inline]
 __x64_sys_unlink+0x35/0x50 fs/namei.c:4108
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 5988:
 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]
 kmem_cache_free+0x83/0x290 mm/slab.c:3760
 putname+0xf2/0x130 fs/namei.c:261
 do_unlinkat+0x236/0xa30 fs/namei.c:4084
 __do_sys_unlink fs/namei.c:4110 [inline]
 __se_sys_unlink fs/namei.c:4108 [inline]
 __x64_sys_unlink+0x42/0x50 fs/namei.c:4108
 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 ffff880187706380
 which belongs to the cache names_cache of size 4096
The buggy address is located 3120 bytes to the right of
 4096-byte region [ffff880187706380, ffff880187707380)
The buggy address belongs to the page:
page:ffffea00061dc180 count:1 mapcount:0 mapping:ffff8801da980e00 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000010200(slab|head)
raw: 02fffc0000010200 ffffea00061dc108 ffffea00061d9a08 ffff8801da980e00
raw: 0000000000000000 ffff880187706380 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff880187707e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff880187707f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff880187707f80: 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc f1
                                     ^
 ffff880187708000: f1 f1 f1 00 f2 f2 f2 f2 f2 f2 f2 f8 f2 f2 f2 00
 ffff880187708080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================