==================================================================
BUG: KASAN: slab-out-of-bounds in ip6_tnl_xmit2+0x1f95/0x2320 net/ipv6/ip6_tunnel.c:987
Read of size 16 at addr ffff8801d6cdf430 by task syz-executor162/2232

CPU: 0 PID: 2232 Comm: syz-executor162 Not tainted 4.4.174+ #4
 0000000000000000 7dfc489a1df6fa71 ffff8801d287edd0 ffffffff81aad1a1
 0000000000000000 ffffea00075b3700 ffff8801d6cdf430 0000000000000010
 ffff8801d6cdf180 ffff8801d287ee08 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
 [<ffffffff823d300e>] ip_send_skb+0x3e/0xc0 net/ipv4/ip_output.c:1453
 [<ffffffff82478ded>] udp_send_skb+0x4fd/0xc70 net/ipv4/udp.c:842
 [<ffffffff8247fb9f>] udp_sendmsg+0x16cf/0x1c60 net/ipv4/udp.c:1072
 [<ffffffff826137a2>] udpv6_sendmsg+0x12f2/0x24f0 net/ipv6/udp.c:1173
 [<ffffffff824a8b42>] inet_sendmsg+0x202/0x4d0 net/ipv4/af_inet.c:755
 [<ffffffff821d838e>] sock_sendmsg_nosec net/socket.c:638 [inline]
 [<ffffffff821d838e>] sock_sendmsg+0xbe/0x110 net/socket.c:648
 [<ffffffff821da269>] ___sys_sendmsg+0x769/0x890 net/socket.c:1975
 [<ffffffff821dd0c5>] __sys_sendmsg+0xc5/0x160 net/socket.c:2009
 [<ffffffff821dd18d>] SYSC_sendmsg net/socket.c:2020 [inline]
 [<ffffffff821dd18d>] SyS_sendmsg+0x2d/0x50 net/socket.c:2016
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a

Allocated by task 2232:
 [<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
 [<ffffffff823d300e>] ip_send_skb+0x3e/0xc0 net/ipv4/ip_output.c:1453
 [<ffffffff82478ded>] udp_send_skb+0x4fd/0xc70 net/ipv4/udp.c:842
 [<ffffffff8247fb9f>] udp_sendmsg+0x16cf/0x1c60 net/ipv4/udp.c:1072
 [<ffffffff826137a2>] udpv6_sendmsg+0x12f2/0x24f0 net/ipv6/udp.c:1173
 [<ffffffff824a8b42>] inet_sendmsg+0x202/0x4d0 net/ipv4/af_inet.c:755
 [<ffffffff821d838e>] sock_sendmsg_nosec net/socket.c:638 [inline]
 [<ffffffff821d838e>] sock_sendmsg+0xbe/0x110 net/socket.c:648
 [<ffffffff821da269>] ___sys_sendmsg+0x769/0x890 net/socket.c:1975
 [<ffffffff821dd0c5>] __sys_sendmsg+0xc5/0x160 net/socket.c:2009
 [<ffffffff821dd18d>] SYSC_sendmsg net/socket.c:2020 [inline]
 [<ffffffff821dd18d>] SyS_sendmsg+0x2d/0x50 net/socket.c:2016
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a

Freed by task 469:
 [<ffffffff8102e3c6>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff81484820>] save_stack mm/kasan/kasan.c:512 [inline]
 [<ffffffff81484820>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff81484820>] kasan_slab_free+0xb0/0x190 mm/kasan/kasan.c:589
 [<ffffffff81481c44>] slab_free_hook mm/slub.c:1383 [inline]
 [<ffffffff81481c44>] slab_free_freelist_hook mm/slub.c:1405 [inline]
 [<ffffffff81481c44>] slab_free mm/slub.c:2859 [inline]
 [<ffffffff81481c44>] kfree+0xf4/0x310 mm/slub.c:3749
 [<ffffffff821fd036>] skb_free_head net/core/skbuff.c:571 [inline]
 [<ffffffff821fd036>] skb_release_data+0x2e6/0x380 net/core/skbuff.c:602
 [<ffffffff821fd11d>] skb_release_all+0x4d/0x60 net/core/skbuff.c:661
 [<ffffffff821ff4b3>] __kfree_skb net/core/skbuff.c:675 [inline]
 [<ffffffff821ff4b3>] consume_skb+0xf3/0x3f0 net/core/skbuff.c:748
 [<ffffffff8220cc1b>] skb_free_datagram+0x1b/0xf0 net/core/datagram.c:280
 [<ffffffff822e8135>] netlink_recvmsg+0x585/0xcf0 net/netlink/af_netlink.c:1938
 [<ffffffff821d8d9f>] sock_recvmsg_nosec net/socket.c:740 [inline]
 [<ffffffff821d8d9f>] sock_recvmsg net/socket.c:748 [inline]
 [<ffffffff821d8d9f>] sock_recvmsg+0x8f/0xc0 net/socket.c:743
 [<ffffffff821da5e7>] ___sys_recvmsg+0x257/0x530 net/socket.c:2129
 [<ffffffff821dd5b5>] __sys_recvmsg+0xc5/0x160 net/socket.c:2175
 [<ffffffff821dd67d>] SYSC_recvmsg net/socket.c:2187 [inline]
 [<ffffffff821dd67d>] SyS_recvmsg+0x2d/0x50 net/socket.c:2182
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a

The buggy address belongs to the object at ffff8801d6cdf180
 which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 688 bytes inside of
 1024-byte region [ffff8801d6cdf180, ffff8801d6cdf580)
The buggy address belongs to the page:
BUG: unable to handle kernel paging request at fffffbfff7be8088
IP: [<ffffffff8115d5dc>] task_curr kernel/sched/core.c:1025 [inline]
IP: [<ffffffff8115d5dc>] kick_process+0xdc/0x1d0 kernel/sched/core.c:1567
PGD 21ff68067 PUD 21ff67067 PMD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 2085 Comm: syz-executor162 Not tainted 4.4.174+ #4
task: ffff8801d4982f80 task.stack: ffff8800b6960000
RIP: 0010:[<ffffffff8115d5dc>]  [<ffffffff8115d5dc>] task_curr kernel/sched/core.c:1025 [inline]
RIP: 0010:[<ffffffff8115d5dc>]  [<ffffffff8115d5dc>] kick_process+0xdc/0x1d0 kernel/sched/core.c:1567
RSP: 0000:ffff8800b69677f8  EFLAGS: 00010806
RAX: dffffc0000000000 RBX: ffff8800b58ac740 RCX: 0000000000000000
RDX: 1ffffffff7be8088 RSI: ffffffff81b0abec RDI: ffffffffbdf40440
RBP: ffff8800b6967818 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: 000000000001e880
R13: 00000000075b3700 R14: 00000000075b3700 R15: ffff8801d2f60000
FS:  0000000000000000(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffbfff7be8088 CR3: 0000000002e0a000 CR4: 00000000001606b0
Stack:
 0000000000000081 ffff8800b58ac740 dffffc0000000000 0000000000000100
 ffff8800b6967838 ffffffff810f877f ffff8800b58ac740 ffff8800b58ac740
 ffff8800b6967890 ffffffff810f9ce2 0000000000000000 0000000000000000
Call Trace:
 [<ffffffff810f877f>] signal_wake_up_state+0x5f/0x70 kernel/signal.c:660
 [<ffffffff810f9ce2>] signal_wake_up include/linux/sched.h:3337 [inline]
 [<ffffffff810f9ce2>] complete_signal+0x632/0x7b0 kernel/signal.c:942
 [<ffffffff810fa3f7>] __send_signal+0x597/0x12a0 kernel/signal.c:1080
 [<ffffffff810fb149>] send_signal+0x49/0xc0 kernel/signal.c:1096
 [<ffffffff810fde34>] do_send_sig_info+0xa4/0x130 kernel/signal.c:1151
 [<ffffffff810fdef6>] send_sig_info+0x36/0x60 kernel/signal.c:1436
 [<ffffffff812db00b>] zap_pid_ns_processes+0x1cb/0x640 kernel/pid_namespace.c:223
 [<ffffffff810da5af>] find_child_reaper kernel/exit.c:485 [inline]
 [<ffffffff810da5af>] forget_original_parent kernel/exit.c:571 [inline]
 [<ffffffff810da5af>] exit_notify kernel/exit.c:607 [inline]
 [<ffffffff810da5af>] do_exit+0x236f/0x2c60 kernel/exit.c:784
 [<ffffffff810df091>] do_group_exit+0x111/0x300 kernel/exit.c:893
 [<ffffffff81100a97>] get_signal+0x517/0x1570 kernel/signal.c:2321
 [<ffffffff8100bd4c>] do_signal+0x9c/0x1840 arch/x86/kernel/signal.c:712
 [<ffffffff81003da7>] exit_to_usermode_loop+0x127/0x170 arch/x86/entry/common.c:184
 [<ffffffff810053ba>] prepare_exit_to_usermode+0x15a/0x1e0 arch/x86/entry/common.c:221
 [<ffffffff82719745>] retint_user+0x8/0x3c
Code: 04 02 84 c0 74 08 3c 03 0f 8e be 00 00 00 48 b8 00 00 00 00 00 fc ff df 45 8b 6d 10 4a 8d 3c ed 40 4c 1a 83 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 b8 00 00 00 4e 03 24 ed 40 4c 1a 83 48 b8 00 
RIP  [<ffffffff8115d5dc>] task_curr kernel/sched/core.c:1025 [inline]
RIP  [<ffffffff8115d5dc>] kick_process+0xdc/0x1d0 kernel/sched/core.c:1567
 RSP <ffff8800b69677f8>
CR2: fffffbfff7be8088
---[ end trace 8ccbe7e050134cf0 ]---