==================================================================
BUG: KASAN: slab-out-of-bounds in ip6_tnl_xmit2+0x1f95/0x2320 net/ipv6/ip6_tunnel.c:987
Read of size 16 at addr ffff8801d8394bb0 by task syz-executor.3/14098

CPU: 1 PID: 14098 Comm: syz-executor.3 Not tainted 4.4.174+ #17
 0000000000000000 844af686f8f3d863 ffff8800a46fec50 ffffffff81aad1a1
 0000000000000000 ffffea000760e500 ffff8801d8394bb0 0000000000000010
 ffff8801d8394900 ffff8800a46fec88 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
 [<ffffffff821d9e69>] ___sys_sendmsg+0x369/0x890 net/socket.c:1975
 [<ffffffff821dd386>] __sys_sendmmsg+0x1d6/0x2e0 net/socket.c:2053
 [<ffffffff822ace22>] C_SYSC_sendmmsg net/compat.c:731 [inline]
 [<ffffffff822ace22>] compat_SyS_sendmmsg+0x32/0x40 net/compat.c:728
 [<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 14098:
 [<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
 [<ffffffff821d9e69>] ___sys_sendmsg+0x369/0x890 net/socket.c:1975
 [<ffffffff821dd386>] __sys_sendmmsg+0x1d6/0x2e0 net/socket.c:2053
 [<ffffffff822ace22>] C_SYSC_sendmmsg net/compat.c:731 [inline]
 [<ffffffff822ace22>] compat_SyS_sendmmsg+0x32/0x40 net/compat.c:728
 [<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 2119:
 [<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
 [<ffffffff81409a1d>] kvfree+0x4d/0x60 mm/util.c:323
 [<ffffffff8236dfdb>] xt_free_table_info+0x14b/0x1b0 net/netfilter/x_tables.c:1019
 [<ffffffff8268cfa5>] translate_compat_table+0x13b5/0x1790 net/ipv6/netfilter/ip6_tables.c:1651
 [<ffffffff8268d5d9>] compat_do_replace.isra.0+0x259/0x3e0 net/ipv6/netfilter/ip6_tables.c:1701
 [<ffffffff8268d865>] compat_do_ip6t_set_ctl+0x105/0x150 net/ipv6/netfilter/ip6_tables.c:1732
 [<ffffffff822fd08b>] compat_nf_sockopt net/netfilter/nf_sockopt.c:143 [inline]
 [<ffffffff822fd08b>] compat_nf_setsockopt+0x8b/0x130 net/netfilter/nf_sockopt.c:155
 [<ffffffff8260057a>] compat_ipv6_setsockopt net/ipv6/ipv6_sockglue.c:940 [inline]
 [<ffffffff8260057a>] compat_ipv6_setsockopt+0x15a/0x1d0 net/ipv6/ipv6_sockglue.c:916
 [<ffffffff823e3719>] inet_csk_compat_setsockopt+0x99/0x120 net/ipv4/inet_connection_sock.c:914
 [<ffffffff823f7770>] compat_tcp_setsockopt+0x40/0x70 net/ipv4/tcp.c:2654
 [<ffffffff821df024>] compat_sock_common_setsockopt+0xb4/0x150 net/core/sock.c:2674
 [<ffffffff822ac2ac>] C_SYSC_setsockopt net/compat.c:385 [inline]
 [<ffffffff822ac2ac>] compat_SyS_setsockopt+0x15c/0x720 net/compat.c:368
 [<ffffffff822ad567>] C_SYSC_socketcall net/compat.c:839 [inline]
 [<ffffffff822ad567>] compat_SyS_socketcall+0x4f7/0x630 net/compat.c:774
 [<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

The buggy address belongs to the object at ffff8801d8394900
 which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 688 bytes inside of
 1024-byte region [ffff8801d8394900, ffff8801d8394d00)
The buggy address belongs to the page:
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 14075 Comm: syz-executor.3 Not tainted 4.4.174+ #17
task: ffff8801d1a15f00 task.stack: ffff8800b8a60000
RIP: 0010:[<ffffffff81b0c66f>]  [<ffffffff81b0c66f>] lookup_object lib/debugobjects.c:120 [inline]
RIP: 0010:[<ffffffff81b0c66f>]  [<ffffffff81b0c66f>] debug_object_deactivate+0x16f/0x360 lib/debugobjects.c:468
RSP: 0018:ffff8801db607d00  EFLAGS: 00010803
RAX: 1ffffffff08110c0 RBX: 0000000000000003 RCX: 000000000000e0de
RDX: 14541d1cf1298164 RSI: ffffffff82eacda0 RDI: a2a0e8e7894c0b27
RBP: ffff8801db607de8 R08: 0000000000000003 R09: ffffffff84088608
R10: 0000000000000096 R11: 0000000000000000 R12: a2a0e8e7894c0b0f
R13: dffffc0000000000 R14: 1ffff1003b6c0fa4 R15: ffffffff8315be08
FS:  0000000000000000(0000) GS:ffff8801db600000(0063) knlGS:00000000f55d5b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000002000a01c CR3: 00000001d97a3000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff88021fffd008 0000000000000006 ffffffff84088608 ffffffff82eacda0
 0000000041b58ab3 ffffffff82c76921 ffffffff81b0c500 0000000000000000
 0000000000000000 ffff8801db607dc8 0000000000000046 0000000000000000
Call Trace:
 <IRQ> 
 [<ffffffff81258d4f>] debug_timer_deactivate kernel/time/timer.c:618 [inline]
 [<ffffffff81258d4f>] debug_deactivate kernel/time/timer.c:670 [inline]
 [<ffffffff81258d4f>] detach_timer kernel/time/timer.c:716 [inline]
 [<ffffffff81258d4f>] detach_expired_timer kernel/time/timer.c:727 [inline]
 [<ffffffff81258d4f>] __run_timers kernel/time/timer.c:1253 [inline]
 [<ffffffff81258d4f>] run_timer_softirq+0x3af/0xb70 kernel/time/timer.c:1444
 [<ffffffff8271bb16>] __do_softirq+0x226/0xa3f kernel/softirq.c:273
 [<ffffffff810e1a8a>] invoke_softirq kernel/softirq.c:350 [inline]
 [<ffffffff810e1a8a>] irq_exit+0x10a/0x150 kernel/softirq.c:391
 [<ffffffff8271b24e>] exiting_irq arch/x86/include/asm/apic.h:652 [inline]
 [<ffffffff8271b24e>] smp_apic_timer_interrupt+0x7e/0xb0 arch/x86/kernel/apic/apic.c:926
 [<ffffffff8271a59d>] apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:768
 <EOI> 
 [<ffffffff81299a20>] smp_call_function_many+0x5c0/0x730 kernel/smp.c:435
 [<ffffffff810bbc70>] native_flush_tlb_others+0x110/0x710 arch/x86/mm/tlb.c:325
 [<ffffffff810bc37e>] flush_tlb_others arch/x86/include/asm/paravirt.h:338 [inline]
 [<ffffffff810bc37e>] flush_tlb_mm_range+0x10e/0x550 arch/x86/mm/tlb.c:391
 [<ffffffff81461f77>] flush_tlb_page arch/x86/include/asm/tlbflush.h:300 [inline]
 [<ffffffff81461f77>] ptep_clear_flush+0xe7/0x120 mm/pgtable-generic.c:80
 [<ffffffff81430223>] wp_page_copy.isra.0+0x6e3/0xc70 mm/memory.c:2202
 [<ffffffff81433bda>] do_wp_page+0x23a/0x1340 mm/memory.c:2441
 [<ffffffff8143b2e4>] handle_pte_fault mm/memory.c:3362 [inline]
 [<ffffffff8143b2e4>] __handle_mm_fault mm/memory.c:3474 [inline]
 [<ffffffff8143b2e4>] handle_mm_fault+0x1614/0x3140 mm/memory.c:3503
 [<ffffffff810aaa4e>] __do_page_fault+0x28e/0x7f0 arch/x86/mm/fault.c:1243
 [<ffffffff810ab008>] do_page_fault+0x28/0x30 arch/x86/mm/fault.c:1306
 [<ffffffff82719e35>] page_fault+0x25/0x30 arch/x86/entry/entry_64.S:1064
 [<ffffffff822ace22>] C_SYSC_sendmmsg net/compat.c:731 [inline]
 [<ffffffff822ace22>] compat_SyS_sendmmsg+0x32/0x40 net/compat.c:728
 [<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
Code: 48 c1 ea 03 42 80 3c 2a 00 0f 85 8e 01 00 00 4d 8b 24 24 4d 85 e4 0f 84 e9 00 00 00 49 8d 7c 24 18 83 c3 01 48 89 fa 48 c1 ea 03 <42> 80 3c 2a 00 0f 85 3f 01 00 00 4d 3b 7c 24 18 75 c0 49 8d 7c 
RIP  [<ffffffff81b0c66f>] lookup_object lib/debugobjects.c:120 [inline]
RIP  [<ffffffff81b0c66f>] debug_object_deactivate+0x16f/0x360 lib/debugobjects.c:468
 RSP <ffff8801db607d00>
---[ end trace 6c4737a0bd267964 ]---