syz-executor4 (13383) used greatest stack depth: 10176 bytes left
==================================================================
BUG: KASAN: slab-out-of-bounds in perf_exclude_event+0x18b/0x1a0 kernel/events/core.c:7895
Read of size 8 at addr ffff88017e5dfff0 by task syz-executor4/13384

CPU: 0 PID: 13384 Comm: syz-executor4 Not tainted 4.19.0-rc7-next-20181012+ #93
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+0x244/0x3ab 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+0x1a1/0x750 arch/x86/kernel/apic/apic.c:1059
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:804
 </IRQ>

Allocated by task 13348:
 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_symlinkat+0x8b/0x2d0 fs/namei.c:4143
 __do_sys_symlink fs/namei.c:4173 [inline]
 __se_sys_symlink fs/namei.c:4171 [inline]
 __x64_sys_symlink+0x59/0x80 fs/namei.c:4171
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 13348:
 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_symlinkat+0x18c/0x2d0 fs/namei.c:4161
 __do_sys_symlink fs/namei.c:4173 [inline]
 __se_sys_symlink fs/namei.c:4171 [inline]
 __x64_sys_symlink+0x59/0x80 fs/namei.c:4171
 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 ffff88017e5de680
 which belongs to the cache names_cache of size 4096
The buggy address is located 2416 bytes to the right of
 4096-byte region [ffff88017e5de680, ffff88017e5df680)
The buggy address belongs to the page:
page:ffffea0005f97780 count:1 mapcount:0 mapping:ffff8801da98ae00 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000010200(slab|head)
raw: 02fffc0000010200 ffffea0005f97708 ffffea0005f97a08 ffff8801da98ae00
raw: 0000000000000000 ffff88017e5de680 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88017e5dfe80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88017e5dff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88017e5dff80: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
                                                             ^
 ffff88017e5e0000: 00 00 00 00 00 00 00 f1 f1 f1 f1 f8 f2 f2 f2 f2
 ffff88017e5e0080: f2 f2 f2 f8 f2 f2 f2 00 00 00 00 00 00 00 00 00
==================================================================