audit: type=1400 audit(1520315387.160:6): avc:  denied  { map } for  pid=4225 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1
audit: type=1400 audit(1520315393.463:7): avc:  denied  { map } for  pid=4239 comm="syzkaller217700" path="/root/syzkaller217700407" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
==================================================================
BUG: KASAN: slab-out-of-bounds in setup_udp_tunnel_sock+0x3ee/0x5f0 net/ipv4/udp_tunnel.c:69
Write of size 1 at addr ffff8801d513c558 by task syzkaller217700/4239

CPU: 0 PID: 4239 Comm: syzkaller217700 Not tainted 4.16.0-rc2+ #253
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+0x194/0x24d 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
 __asan_report_store1_noabort+0x17/0x20 mm/kasan/report.c:435
 setup_udp_tunnel_sock+0x3ee/0x5f0 net/ipv4/udp_tunnel.c:69
 l2tp_tunnel_create+0x1354/0x17f0 net/l2tp/l2tp_core.c:1596
 pppol2tp_connect+0x14b1/0x1dd0 net/l2tp/l2tp_ppp.c:707
 SYSC_connect+0x213/0x4a0 net/socket.c:1640
 SyS_connect+0x24/0x30 net/socket.c:1621
 do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x43fd99
RSP: 002b:00007ffe83de9be8 EFLAGS: 00000217 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fd99
RDX: 000000000000002e RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000217 R12: 00000000004016c0
R13: 0000000000401750 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 4239:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:552
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3541
 sk_prot_alloc+0x65/0x2a0 net/core/sock.c:1469
 sk_alloc+0x105/0x1440 net/core/sock.c:1529
 inet_create+0x47c/0xf50 net/ipv4/af_inet.c:320
 __sock_create+0x4d4/0x850 net/socket.c:1285
 sock_create net/socket.c:1325 [inline]
 SYSC_socket net/socket.c:1355 [inline]
 SyS_socket+0xeb/0x1d0 net/socket.c:1335
 do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8801d513c040
 which belongs to the cache RAW of size 1304
The buggy address is located 0 bytes to the right of
 1304-byte region [ffff8801d513c040, ffff8801d513c558)
The buggy address belongs to the page:
page:ffffea0007544f00 count:1 mapcount:0 mapping:ffff8801d513c040 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffff8801d513c040 0000000000000000 0000000100000005
raw: ffff8801d5870848 ffff8801d5870848 ffff8801d6be8640 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d513c400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801d513c480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801d513c500: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
                                                    ^
 ffff8801d513c580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801d513c600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================