==================================================================
BUG: KASAN: slab-out-of-bounds in ip6_tnl_xmit2+0x229d/0x2350 net/ipv6/ip6_tunnel.c:987
Read of size 16 at addr ffff8801d2abefb0 by task syz-executor175/2501

CPU: 0 PID: 2501 Comm: syz-executor175 Not tainted 4.4.162+ #117
 0000000000000000 e66fffc6500fbc73 ffff8801d1af6ca0 ffffffff81a994bd
 ffffea00074aaf00 ffff8801d2abefb0 0000000000000000 ffff8801d2abefb8
 ffff8800bb89c400 ffff8801d1af6cd8 ffffffff8148a669 ffff8801d2abefb0
Call Trace:
 [<ffffffff81a994bd>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81a994bd>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff8148a669>] print_address_description+0x6c/0x217 mm/kasan/report.c:252
 [<ffffffff8148a989>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff8148a989>] kasan_report.cold.6+0x175/0x2f7 mm/kasan/report.c:408
 [<ffffffff8147f6df>] __asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:439
 [<ffffffff826a1e9d>] ip6_tnl_xmit2+0x229d/0x2350 net/ipv6/ip6_tunnel.c:987
 [<ffffffff826a3949>] ip4ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1134 [inline]
 [<ffffffff826a3949>] ip6_tnl_xmit+0x9f9/0xe10 net/ipv6/ip6_tunnel.c:1212
 [<ffffffff82230d3d>] __netdev_start_xmit include/linux/netdevice.h:3750 [inline]
 [<ffffffff82230d3d>] netdev_start_xmit include/linux/netdevice.h:3759 [inline]
 [<ffffffff82230d3d>] xmit_one net/core/dev.c:2781 [inline]
 [<ffffffff82230d3d>] dev_hard_start_xmit+0x7bd/0x11c0 net/core/dev.c:2797
 [<ffffffff822330f5>] __dev_queue_xmit+0x16f5/0x1c30 net/core/dev.c:3229
 [<ffffffff82233647>] dev_queue_xmit+0x17/0x20 net/core/dev.c:3263
 [<ffffffff822483c5>] neigh_direct_output+0x15/0x20 net/core/neighbour.c:1369
 [<ffffffff823b3b50>] dst_neigh_output include/net/dst.h:461 [inline]
 [<ffffffff823b3b50>] ip_finish_output2+0x8f0/0x1100 net/ipv4/ip_output.c:213
 [<ffffffff823ba9e2>] ip_finish_output+0x882/0xc00 net/ipv4/ip_output.c:288
 [<ffffffff823be5d9>] NF_HOOK_COND include/linux/netfilter.h:240 [inline]
 [<ffffffff823be5d9>] ip_output+0x219/0x4c0 net/ipv4/ip_output.c:362
 [<ffffffff823bb4fb>] dst_output include/net/dst.h:498 [inline]
 [<ffffffff823bb4fb>] ip_local_out+0x9b/0x180 net/ipv4/ip_output.c:119
 [<ffffffff823c121c>] ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1453
 [<ffffffff82466373>] udp_send_skb+0x503/0xc70 net/ipv4/udp.c:842
 [<ffffffff8246d1f9>] udp_sendmsg+0x16c9/0x1c70 net/ipv4/udp.c:1072
 [<ffffffff8260127d>] udpv6_sendmsg+0x12cd/0x24c0 net/ipv6/udp.c:1173
 [<ffffffff82496493>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:755
 [<ffffffff821c376b>] sock_sendmsg_nosec net/socket.c:638 [inline]
 [<ffffffff821c376b>] sock_sendmsg+0xbb/0x110 net/socket.c:648
 [<ffffffff821c55b5>] ___sys_sendmsg+0x745/0x880 net/socket.c:1975
 [<ffffffff821c8606>] __sys_sendmsg+0xd6/0x190 net/socket.c:2009
 [<ffffffff821c86ed>] SYSC_sendmsg net/socket.c:2020 [inline]
 [<ffffffff821c86ed>] SyS_sendmsg+0x2d/0x50 net/socket.c:2016
 [<ffffffff827062e1>] entry_SYSCALL_64_fastpath+0x1e/0x9a

Allocated by task 2501:
 [<ffffffff8102e496>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff8147e642>] save_stack mm/kasan/kasan.c:512 [inline]
 [<ffffffff8147e642>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff8147e642>] kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:616
 [<ffffffff8147e8bf>] kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:601
 [<ffffffff8147ac0d>] __kmalloc+0x13d/0x330 mm/slub.c:3613
 [<ffffffff822505e6>] kmalloc include/linux/slab.h:481 [inline]
 [<ffffffff822505e6>] kzalloc include/linux/slab.h:620 [inline]
 [<ffffffff822505e6>] neigh_alloc net/core/neighbour.c:285 [inline]
 [<ffffffff822505e6>] __neigh_create+0x1d6/0x1b20 net/core/neighbour.c:457
 [<ffffffff8238dd8e>] neigh_create include/net/neighbour.h:313 [inline]
 [<ffffffff8238dd8e>] ipv4_neigh_lookup+0x4de/0x700 net/ipv4/route.c:464
 [<ffffffff8269fe8a>] dst_neigh_lookup include/net/dst.h:466 [inline]
 [<ffffffff8269fe8a>] ip6_tnl_xmit2+0x28a/0x2350 net/ipv6/ip6_tunnel.c:982
 [<ffffffff826a3949>] ip4ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1134 [inline]
 [<ffffffff826a3949>] ip6_tnl_xmit+0x9f9/0xe10 net/ipv6/ip6_tunnel.c:1212
 [<ffffffff82230d3d>] __netdev_start_xmit include/linux/netdevice.h:3750 [inline]
 [<ffffffff82230d3d>] netdev_start_xmit include/linux/netdevice.h:3759 [inline]
 [<ffffffff82230d3d>] xmit_one net/core/dev.c:2781 [inline]
 [<ffffffff82230d3d>] dev_hard_start_xmit+0x7bd/0x11c0 net/core/dev.c:2797
 [<ffffffff822330f5>] __dev_queue_xmit+0x16f5/0x1c30 net/core/dev.c:3229
 [<ffffffff82233647>] dev_queue_xmit+0x17/0x20 net/core/dev.c:3263
 [<ffffffff822483c5>] neigh_direct_output+0x15/0x20 net/core/neighbour.c:1369
 [<ffffffff823b3b50>] dst_neigh_output include/net/dst.h:461 [inline]
 [<ffffffff823b3b50>] ip_finish_output2+0x8f0/0x1100 net/ipv4/ip_output.c:213
 [<ffffffff823ba9e2>] ip_finish_output+0x882/0xc00 net/ipv4/ip_output.c:288
 [<ffffffff823be5d9>] NF_HOOK_COND include/linux/netfilter.h:240 [inline]
 [<ffffffff823be5d9>] ip_output+0x219/0x4c0 net/ipv4/ip_output.c:362
 [<ffffffff823bb4fb>] dst_output include/net/dst.h:498 [inline]
 [<ffffffff823bb4fb>] ip_local_out+0x9b/0x180 net/ipv4/ip_output.c:119
 [<ffffffff823c121c>] ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1453
 [<ffffffff82466373>] udp_send_skb+0x503/0xc70 net/ipv4/udp.c:842
 [<ffffffff8246d1f9>] udp_sendmsg+0x16c9/0x1c70 net/ipv4/udp.c:1072
 [<ffffffff8260127d>] udpv6_sendmsg+0x12cd/0x24c0 net/ipv6/udp.c:1173
 [<ffffffff82496493>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:755
 [<ffffffff821c376b>] sock_sendmsg_nosec net/socket.c:638 [inline]
 [<ffffffff821c376b>] sock_sendmsg+0xbb/0x110 net/socket.c:648
 [<ffffffff821c55b5>] ___sys_sendmsg+0x745/0x880 net/socket.c:1975
 [<ffffffff821c8606>] __sys_sendmsg+0xd6/0x190 net/socket.c:2009
 [<ffffffff821c86ed>] SYSC_sendmsg net/socket.c:2020 [inline]
 [<ffffffff821c86ed>] SyS_sendmsg+0x2d/0x50 net/socket.c:2016
 [<ffffffff827062e1>] entry_SYSCALL_64_fastpath+0x1e/0x9a

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8801d2abed00
 which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 688 bytes inside of
 1024-byte region [ffff8801d2abed00, ffff8801d2abf100)
The buggy address belongs to the page:
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access[   38.697204] ------------[ cut here ]------------
WARNING: CPU: 1 PID: 2079 at kernel/sched/core.c:7946 __might_sleep+0x138/0x1a0 kernel/sched/core.c:7941()
do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffff810de9e0>] do_wait+0x270/0xa30 kernel/exit.c:1503