==================================================================
BUG: KASAN: slab-out-of-bounds in ip6_tnl_xmit2+0x1f95/0x2320 net/ipv6/ip6_tunnel.c:987
Read of size 16 at addr ffff8800b630f430 by task syz-executor.2/5713

CPU: 1 PID: 5713 Comm: syz-executor.2 Not tainted 4.4.174+ #17
 0000000000000000 26a101f0c4c57b9f ffff8800b39f7230 ffffffff81aad1a1
 0000000000000000 ffffea0002d8c300 ffff8800b630f430 0000000000000010
 ffff8800b630f180 ffff8800b39f7268 ffffffff81490120 0000000000000000
Call Trace:
 [<ffffffff81aad1a1>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81aad1a1>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<ffffffff81490120>] print_address_description+0x6f/0x21b mm/kasan/report.c:252
 [<ffffffff81490358>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff81490358>] kasan_report mm/kasan/report.c:408 [inline]
 [<ffffffff81490358>] kasan_report.cold+0x8c/0x2be mm/kasan/report.c:393
 [<ffffffff81484faf>] __asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:439
 [<ffffffff826b3105>] ip6_tnl_xmit2+0x1f95/0x2320 net/ipv6/ip6_tunnel.c:987
 [<ffffffff826b4e59>] ip4ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1134 [inline]
 [<ffffffff826b4e59>] ip6_tnl_xmit+0xa09/0xe00 net/ipv6/ip6_tunnel.c:1212
 [<ffffffff82245071>] __netdev_start_xmit include/linux/netdevice.h:3750 [inline]
 [<ffffffff82245071>] netdev_start_xmit include/linux/netdevice.h:3759 [inline]
 [<ffffffff82245071>] xmit_one net/core/dev.c:2781 [inline]
 [<ffffffff82245071>] dev_hard_start_xmit+0x7c1/0x11e0 net/core/dev.c:2797
 [<ffffffff822473cb>] __dev_queue_xmit+0x164b/0x1bb0 net/core/dev.c:3229
 [<ffffffff82247948>] dev_queue_xmit+0x18/0x20 net/core/dev.c:3263
 [<ffffffff8225c136>] neigh_direct_output+0x16/0x20 net/core/neighbour.c:1369
 [<ffffffff823c5412>] dst_neigh_output include/net/dst.h:461 [inline]
 [<ffffffff823c5412>] ip_finish_output2+0x6a2/0x1280 net/ipv4/ip_output.c:213
 [<ffffffff823cc6e2>] ip_finish_output+0x8b2/0xc60 net/ipv4/ip_output.c:288
 [<ffffffff823d04a7>] NF_HOOK_COND include/linux/netfilter.h:240 [inline]
 [<ffffffff823d04a7>] ip_output+0x227/0x4c0 net/ipv4/ip_output.c:362
 [<ffffffff823cd21c>] dst_output include/net/dst.h:498 [inline]
 [<ffffffff823cd21c>] ip_local_out+0x9c/0x180 net/ipv4/ip_output.c:119
 [<ffffffff823ce58c>] ip_queue_xmit+0x89c/0x1ab0 net/ipv4/ip_output.c:461
 [<ffffffff82431dd4>] __tcp_transmit_skb+0x1904/0x2cf0 net/ipv4/tcp_output.c:1034
input: syz0 as /devices/virtual/input/input20
 [<ffffffff824337e4>] tcp_transmit_skb net/ipv4/tcp_output.c:1047 [inline]
 [<ffffffff824337e4>] tcp_write_xmit+0x624/0x4570 net/ipv4/tcp_output.c:2137
 [<ffffffff82437fcb>] __tcp_push_pending_frames+0xab/0x2b0 net/ipv4/tcp_output.c:2323
 [<ffffffff8243eeab>] tcp_send_fin+0x15b/0xa90 net/ipv4/tcp_output.c:2899
 [<ffffffff823f5b02>] tcp_shutdown net/ipv4/tcp.c:2008 [inline]
 [<ffffffff823f5b02>] tcp_shutdown+0xe2/0x110 net/ipv4/tcp.c:1993
 [<ffffffff824a675b>] inet_shutdown+0x17b/0x360 net/ipv4/af_inet.c:825
 [<ffffffff821dcf5b>] SYSC_shutdown net/socket.c:1832 [inline]
 [<ffffffff821dcf5b>] SyS_shutdown+0xfb/0x1a0 net/socket.c:1823
 [<ffffffff8100603d>] do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline]
 [<ffffffff8100603d>] do_fast_syscall_32+0x32d/0xa90 arch/x86/entry/common.c:397
 [<ffffffff8271a350>] sysenter_flags_fixed+0xd/0x1a

Allocated by task 5713:
 [<ffffffff8102e3c6>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff81483f22>] save_stack mm/kasan/kasan.c:512 [inline]
 [<ffffffff81483f22>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff81483f22>] kasan_kmalloc.part.0+0x62/0xf0 mm/kasan/kasan.c:616
 [<ffffffff81484197>] kasan_kmalloc+0xb7/0xd0 mm/kasan/kasan.c:601
 [<ffffffff81480521>] __kmalloc+0x141/0x330 mm/slub.c:3613
 [<ffffffff82264216>] kmalloc include/linux/slab.h:481 [inline]
 [<ffffffff82264216>] kzalloc include/linux/slab.h:620 [inline]
 [<ffffffff82264216>] neigh_alloc net/core/neighbour.c:285 [inline]
 [<ffffffff82264216>] __neigh_create+0x1d6/0x1b30 net/core/neighbour.c:457
 [<ffffffff823a024e>] neigh_create include/net/neighbour.h:313 [inline]
 [<ffffffff823a024e>] ipv4_neigh_lookup+0x52e/0x6e0 net/ipv4/route.c:464
 [<ffffffff826b13eb>] dst_neigh_lookup include/net/dst.h:466 [inline]
 [<ffffffff826b13eb>] ip6_tnl_xmit2+0x27b/0x2320 net/ipv6/ip6_tunnel.c:982
 [<ffffffff826b4e59>] ip4ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1134 [inline]
 [<ffffffff826b4e59>] ip6_tnl_xmit+0xa09/0xe00 net/ipv6/ip6_tunnel.c:1212
 [<ffffffff82245071>] __netdev_start_xmit include/linux/netdevice.h:3750 [inline]
 [<ffffffff82245071>] netdev_start_xmit include/linux/netdevice.h:3759 [inline]
 [<ffffffff82245071>] xmit_one net/core/dev.c:2781 [inline]
 [<ffffffff82245071>] dev_hard_start_xmit+0x7c1/0x11e0 net/core/dev.c:2797
 [<ffffffff822473cb>] __dev_queue_xmit+0x164b/0x1bb0 net/core/dev.c:3229
 [<ffffffff82247948>] dev_queue_xmit+0x18/0x20 net/core/dev.c:3263
 [<ffffffff8225c136>] neigh_direct_output+0x16/0x20 net/core/neighbour.c:1369
 [<ffffffff823c5412>] dst_neigh_output include/net/dst.h:461 [inline]
 [<ffffffff823c5412>] ip_finish_output2+0x6a2/0x1280 net/ipv4/ip_output.c:213
 [<ffffffff823cc6e2>] ip_finish_output+0x8b2/0xc60 net/ipv4/ip_output.c:288
 [<ffffffff823d04a7>] NF_HOOK_COND include/linux/netfilter.h:240 [inline]
 [<ffffffff823d04a7>] ip_output+0x227/0x4c0 net/ipv4/ip_output.c:362
 [<ffffffff823cd21c>] dst_output include/net/dst.h:498 [inline]
 [<ffffffff823cd21c>] ip_local_out+0x9c/0x180 net/ipv4/ip_output.c:119
 [<ffffffff823ce58c>] ip_queue_xmit+0x89c/0x1ab0 net/ipv4/ip_output.c:461
 [<ffffffff82431dd4>] __tcp_transmit_skb+0x1904/0x2cf0 net/ipv4/tcp_output.c:1034
 [<ffffffff824337e4>] tcp_transmit_skb net/ipv4/tcp_output.c:1047 [inline]
 [<ffffffff824337e4>] tcp_write_xmit+0x624/0x4570 net/ipv4/tcp_output.c:2137
 [<ffffffff82437fcb>] __tcp_push_pending_frames+0xab/0x2b0 net/ipv4/tcp_output.c:2323
 [<ffffffff8243eeab>] tcp_send_fin+0x15b/0xa90 net/ipv4/tcp_output.c:2899
 [<ffffffff823f5b02>] tcp_shutdown net/ipv4/tcp.c:2008 [inline]
 [<ffffffff823f5b02>] tcp_shutdown+0xe2/0x110 net/ipv4/tcp.c:1993
 [<ffffffff824a675b>] inet_shutdown+0x17b/0x360 net/ipv4/af_inet.c:825
 [<ffffffff821dcf5b>] SYSC_shutdown net/socket.c:1832 [inline]
 [<ffffffff821dcf5b>] SyS_shutdown+0xfb/0x1a0 net/socket.c:1823
 [<ffffffff8100603d>] do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline]
 [<ffffffff8100603d>] do_fast_syscall_32+0x32d/0xa90 arch/x86/entry/common.c:397
 [<ffffffff8271a350>] sysenter_flags_fixed+0xd/0x1a

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8800b630f180
 which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 688 bytes inside of
 1024-byte region [ffff8800b630f180, ffff8800b630f580)
The buggy address belongs to the page: