==================================================================
BUG: KASAN: slab-out-of-bounds in __ipv6_addr_type+0x26c/0x290 net/ipv6/addrconf_core.c:68
Read of size 4 at addr ffff8800b893bd38 by task syz-executor1/20602

CPU: 0 PID: 20602 Comm: syz-executor1 Not tainted 4.4.162+ #3
 0000000000000000 0086d5f09952c937 ffff8800b32a6b10 ffffffff81a994bd
 ffffea0002e24e00 ffff8800b893bd38 0000000000000000 ffff8800b893bd38
 ffff8801c2d53300 ffff8800b32a6b48 ffffffff8148a669 ffff8800b893bd38
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
 [<ffffffff8147f5e4>] __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:428
 [<ffffffff826aa5ec>] __ipv6_addr_type+0x26c/0x290 net/ipv6/addrconf_core.c:68
 [<ffffffff8269fb9b>] ipv6_addr_type include/net/ipv6.h:337 [inline]
 [<ffffffff8269fb9b>] ip6_tnl_xmit2+0x2bb/0x2350 net/ipv6/ip6_tunnel.c:988
 [<ffffffff826a3629>] ip4ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1134 [inline]
 [<ffffffff826a3629>] ip6_tnl_xmit+0x9f9/0xe10 net/ipv6/ip6_tunnel.c:1212
 [<ffffffff82230a1d>] __netdev_start_xmit include/linux/netdevice.h:3750 [inline]
 [<ffffffff82230a1d>] netdev_start_xmit include/linux/netdevice.h:3759 [inline]
 [<ffffffff82230a1d>] xmit_one net/core/dev.c:2781 [inline]
 [<ffffffff82230a1d>] dev_hard_start_xmit+0x7bd/0x11c0 net/core/dev.c:2797
 [<ffffffff82232dd5>] __dev_queue_xmit+0x16f5/0x1c30 net/core/dev.c:3229
 [<ffffffff82233327>] dev_queue_xmit+0x17/0x20 net/core/dev.c:3263
 [<ffffffff822480a5>] neigh_direct_output+0x15/0x20 net/core/neighbour.c:1369
 [<ffffffff823b3830>] dst_neigh_output include/net/dst.h:461 [inline]
 [<ffffffff823b3830>] ip_finish_output2+0x8f0/0x1100 net/ipv4/ip_output.c:213
 [<ffffffff823ba6c2>] ip_finish_output+0x882/0xc00 net/ipv4/ip_output.c:288
 [<ffffffff823be2b9>] NF_HOOK_COND include/linux/netfilter.h:240 [inline]
 [<ffffffff823be2b9>] ip_output+0x219/0x4c0 net/ipv4/ip_output.c:362
 [<ffffffff823bb1db>] dst_output include/net/dst.h:498 [inline]
 [<ffffffff823bb1db>] ip_local_out+0x9b/0x180 net/ipv4/ip_output.c:119
 [<ffffffff823c0efc>] ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1453
 [<ffffffff82466053>] udp_send_skb+0x503/0xc70 net/ipv4/udp.c:842
 [<ffffffff8246ced9>] udp_sendmsg+0x16c9/0x1c70 net/ipv4/udp.c:1072
 [<ffffffff82600f5d>] udpv6_sendmsg+0x12cd/0x24c0 net/ipv6/udp.c:1173
 [<ffffffff82496173>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:755
 [<ffffffff821c344b>] sock_sendmsg_nosec net/socket.c:638 [inline]
 [<ffffffff821c344b>] sock_sendmsg+0xbb/0x110 net/socket.c:648
 [<ffffffff821c4f91>] ___sys_sendmsg+0x441/0x880 net/socket.c:1975
 [<ffffffff821c85c4>] __sys_sendmmsg+0x1d4/0x2e0 net/socket.c:2053
 [<ffffffff82299512>] C_SYSC_sendmmsg net/compat.c:728 [inline]
 [<ffffffff82299512>] compat_SyS_sendmmsg+0x32/0x40 net/compat.c:725
 [<ffffffff8100629e>] do_syscall_32_irqs_on arch/x86/entry/common.c:396 [inline]
 [<ffffffff8100629e>] do_fast_syscall_32+0x31e/0xa80 arch/x86/entry/common.c:463
 [<ffffffff82707750>] sysenter_flags_fixed+0xd/0x1a

Allocated by task 20602:
 [<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
 [<ffffffff822502c6>] kmalloc include/linux/slab.h:481 [inline]
 [<ffffffff822502c6>] kzalloc include/linux/slab.h:620 [inline]
 [<ffffffff822502c6>] neigh_alloc net/core/neighbour.c:285 [inline]
 [<ffffffff822502c6>] __neigh_create+0x1d6/0x1b20 net/core/neighbour.c:457
 [<ffffffff8238da6e>] neigh_create include/net/neighbour.h:313 [inline]
 [<ffffffff8238da6e>] ipv4_neigh_lookup+0x4de/0x700 net/ipv4/route.c:464
 [<ffffffff8269fb6a>] dst_neigh_lookup include/net/dst.h:466 [inline]
 [<ffffffff8269fb6a>] ip6_tnl_xmit2+0x28a/0x2350 net/ipv6/ip6_tunnel.c:982
 [<ffffffff826a3629>] ip4ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1134 [inline]
 [<ffffffff826a3629>] ip6_tnl_xmit+0x9f9/0xe10 net/ipv6/ip6_tunnel.c:1212
 [<ffffffff82230a1d>] __netdev_start_xmit include/linux/netdevice.h:3750 [inline]
 [<ffffffff82230a1d>] netdev_start_xmit include/linux/netdevice.h:3759 [inline]
 [<ffffffff82230a1d>] xmit_one net/core/dev.c:2781 [inline]
 [<ffffffff82230a1d>] dev_hard_start_xmit+0x7bd/0x11c0 net/core/dev.c:2797
 [<ffffffff82232dd5>] __dev_queue_xmit+0x16f5/0x1c30 net/core/dev.c:3229
 [<ffffffff82233327>] dev_queue_xmit+0x17/0x20 net/core/dev.c:3263
 [<ffffffff822480a5>] neigh_direct_output+0x15/0x20 net/core/neighbour.c:1369
 [<ffffffff823b3830>] dst_neigh_output include/net/dst.h:461 [inline]
 [<ffffffff823b3830>] ip_finish_output2+0x8f0/0x1100 net/ipv4/ip_output.c:213
 [<ffffffff823ba6c2>] ip_finish_output+0x882/0xc00 net/ipv4/ip_output.c:288
 [<ffffffff823be2b9>] NF_HOOK_COND include/linux/netfilter.h:240 [inline]
 [<ffffffff823be2b9>] ip_output+0x219/0x4c0 net/ipv4/ip_output.c:362
 [<ffffffff823bb1db>] dst_output include/net/dst.h:498 [inline]
 [<ffffffff823bb1db>] ip_local_out+0x9b/0x180 net/ipv4/ip_output.c:119
 [<ffffffff823c0efc>] ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1453
 [<ffffffff82466053>] udp_send_skb+0x503/0xc70 net/ipv4/udp.c:842
 [<ffffffff8246ced9>] udp_sendmsg+0x16c9/0x1c70 net/ipv4/udp.c:1072
 [<ffffffff82600f5d>] udpv6_sendmsg+0x12cd/0x24c0 net/ipv6/udp.c:1173
 [<ffffffff82496173>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:755
 [<ffffffff821c344b>] sock_sendmsg_nosec net/socket.c:638 [inline]
 [<ffffffff821c344b>] sock_sendmsg+0xbb/0x110 net/socket.c:648
 [<ffffffff821c4f91>] ___sys_sendmsg+0x441/0x880 net/socket.c:1975
 [<ffffffff821c85c4>] __sys_sendmmsg+0x1d4/0x2e0 net/socket.c:2053
 [<ffffffff82299512>] C_SYSC_sendmmsg net/compat.c:728 [inline]
 [<ffffffff82299512>] compat_SyS_sendmmsg+0x32/0x40 net/compat.c:725
 [<ffffffff8100629e>] do_syscall_32_irqs_on arch/x86/entry/common.c:396 [inline]
 [<ffffffff8100629e>] do_fast_syscall_32+0x31e/0xa80 arch/x86/entry/common.c:463
 [<ffffffff82707750>] sysenter_flags_fixed+0xd/0x1a

Freed by task 19217:
 [<ffffffff8102e496>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff8147ef3c>] save_stack mm/kasan/kasan.c:512 [inline]
 [<ffffffff8147ef3c>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff8147ef3c>] kasan_slab_free+0xac/0x190 mm/kasan/kasan.c:589
 [<ffffffff8147c314>] slab_free_hook mm/slub.c:1383 [inline]
 [<ffffffff8147c314>] slab_free_freelist_hook mm/slub.c:1405 [inline]
 [<ffffffff8147c314>] slab_free mm/slub.c:2859 [inline]
 [<ffffffff8147c314>] kfree+0xf4/0x310 mm/slub.c:3749
 [<ffffffff82173ed8>] snd_timer_user_release+0xc8/0x130 sound/core/timer.c:1356
 [<ffffffff81496bc5>] __fput+0x235/0x6f0 fs/file_table.c:208
 [<ffffffff81497105>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff8112ef7f>] task_work_run+0x10f/0x190 kernel/task_work.c:115
 [<ffffffff81003edd>] tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 [<ffffffff81003edd>] exit_to_usermode_loop+0x13d/0x160 arch/x86/entry/common.c:254
 [<ffffffff81006712>] prepare_exit_to_usermode arch/x86/entry/common.c:287 [inline]
 [<ffffffff81006712>] syscall_return_slowpath arch/x86/entry/common.c:352 [inline]
 [<ffffffff81006712>] do_syscall_32_irqs_on arch/x86/entry/common.c:402 [inline]
 [<ffffffff81006712>] do_fast_syscall_32+0x792/0xa80 arch/x86/entry/common.c:463
 [<ffffffff82707750>] sysenter_flags_fixed+0xd/0x1a

The buggy address belongs to the object at ffff8800b893ba80
 which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 696 bytes inside of
 1024-byte region [ffff8800b893ba80, ffff8800b893be80)
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[  693.564125] ------------[ cut here ]------------
WARNING: CPU: 1 PID: 2133 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