==================================================================
BUG: KASAN: use-after-free in memcpy include/linux/string.h:344 [inline]
BUG: KASAN: use-after-free in array_map_update_elem+0x197/0x240 kernel/bpf/arraymap.c:249
Write of size 1 at addr ffff8801c68ea000 by task syz-executor3/8519

CPU: 1 PID: 8519 Comm: syz-executor3 Not tainted 4.15.0-rc7-mm1+ #53
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 print_address_description+0x73/0x250 mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report+0x23b/0x360 mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x137/0x190 mm/kasan/kasan.c:267
 memcpy+0x37/0x50 mm/kasan/kasan.c:303
 memcpy include/linux/string.h:344 [inline]
 array_map_update_elem+0x197/0x240 kernel/bpf/arraymap.c:249
 map_update_elem kernel/bpf/syscall.c:687 [inline]
 SYSC_bpf kernel/bpf/syscall.c:1811 [inline]
 SyS_bpf+0x32df/0x4400 kernel/bpf/syscall.c:1782
 entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x452ac9
RSP: 002b:00007f651b7d0c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f651b7d1700 RCX: 0000000000452ac9
RDX: 0000000000000020 RSI: 0000000020eaf000 RDI: 0000000000000002
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000
R13: 0000000000a2f7ef R14: 00007f651b7d19c0 R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea00071a3a80 count:0 mapcount:0 mapping:          (null) index:0xffff8801c68ead00
flags: 0x2fffc0000000000()
raw: 02fffc0000000000 0000000000000000 ffff8801c68ead00 00000000ffffffff
raw: 0000000000000000 dead000000000200 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c68e9f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8801c68e9f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8801c68ea000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff8801c68ea080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8801c68ea100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 8519 Comm: syz-executor3 Tainted: G    B            4.15.0-rc7-mm1+ #53
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 panic+0x1e4/0x41c kernel/panic.c:183
 kasan_end_report+0x50/0x50 mm/kasan/report.c:180
 kasan_report_error mm/kasan/report.c:359 [inline]
 kasan_report+0x148/0x360 mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x137/0x190 mm/kasan/kasan.c:267
 memcpy+0x37/0x50 mm/kasan/kasan.c:303
 memcpy include/linux/string.h:344 [inline]
 array_map_update_elem+0x197/0x240 kernel/bpf/arraymap.c:249
 map_update_elem kernel/bpf/syscall.c:687 [inline]
 SYSC_bpf kernel/bpf/syscall.c:1811 [inline]
 SyS_bpf+0x32df/0x4400 kernel/bpf/syscall.c:1782
 entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x452ac9
RSP: 002b:00007f651b7d0c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f651b7d1700 RCX: 0000000000452ac9
RDX: 0000000000000020 RSI: 0000000020eaf000 RDI: 0000000000000002
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000
R13: 0000000000a2f7ef R14: 00007f651b7d19c0 R15: 0000000000000000
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..