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BUG: KASAN: slab-out-of-bounds in sock_net_uid include/net/sock.h:1733 [inline]
BUG: KASAN: slab-out-of-bounds in ip6_route_me_harder+0x9d8/0xc00 net/ipv6/netfilter.c:26
Read of size 4 at addr ffff8801b8a60fe8 by task syz-executor1/16935

CPU: 0 PID: 16935 Comm: syz-executor1 Not tainted 4.16.0-rc2+ #250
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x24d lib/dump_stack.c:53
 print_address_description+0x73/0x250 mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report+0x23b/0x360 mm/kasan/report.c:412
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432
 sock_net_uid include/net/sock.h:1733 [inline]
 ip6_route_me_harder+0x9d8/0xc00 net/ipv6/netfilter.c:26
 nf_nat_ipv6_local_fn+0x2a4/0x5d0 net/ipv6/netfilter/nf_nat_l3proto_ipv6.c:414
 ip6table_nat_local_fn+0x2c/0x40 net/ipv6/netfilter/ip6table_nat.c:69
 nf_hook_entry_hookfn include/linux/netfilter.h:120 [inline]
 nf_hook_slow+0xba/0x1a0 net/netfilter/core.c:483
 nf_hook include/linux/netfilter.h:243 [inline]
 NF_HOOK include/linux/netfilter.h:286 [inline]
 ip6_xmit+0x10ec/0x2260 net/ipv6/ip6_output.c:277
 tcp_v6_send_synack+0x57b/0xaa0 net/ipv6/tcp_ipv6.c:490
 tcp_conn_request+0x26fd/0x3660 net/ipv4/tcp_input.c:6335
 tcp_v6_conn_request+0x212/0x270 net/ipv6/tcp_ipv6.c:1021
 tcp_rcv_state_process+0x92a/0x4760 net/ipv4/tcp_input.c:5842
 tcp_v6_do_rcv+0x739/0x1250 net/ipv6/tcp_ipv6.c:1331
 tcp_v6_rcv+0x25a0/0x2d40 net/ipv6/tcp_ipv6.c:1521
 ip6_input_finish+0x37e/0x17a0 net/ipv6/ip6_input.c:284
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_input+0xdb/0x560 net/ipv6/ip6_input.c:327
 dst_input include/net/dst.h:449 [inline]
 ip6_rcv_finish+0x297/0x8c0 net/ipv6/ip6_input.c:71
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ipv6_rcv+0xf37/0x1fa0 net/ipv6/ip6_input.c:208
 __netif_receive_skb_core+0x1a41/0x3460 net/core/dev.c:4554
 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4619
 netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4693
 netif_receive_skb+0xae/0x390 net/core/dev.c:4717
 tun_rx_batched.isra.52+0x5ee/0x870 drivers/net/tun.c:1556
 tun_get_user+0x25a5/0x3810 drivers/net/tun.c:1957
 tun_chr_write_iter+0xbd/0x1c0 drivers/net/tun.c:1985
 call_write_iter include/linux/fs.h:1781 [inline]
 do_iter_readv_writev+0x55c/0x830 fs/read_write.c:653
 do_iter_write+0x154/0x540 fs/read_write.c:932
 vfs_writev+0x18a/0x340 fs/read_write.c:977
 do_writev+0xfc/0x2a0 fs/read_write.c:1012
 SYSC_writev fs/read_write.c:1085 [inline]
 SyS_writev+0x27/0x30 fs/read_write.c:1082
 do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x453c41
RSP: 002b:00007ff749487ba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 000000000000004a RCX: 0000000000453c41
RDX: 0000000000000001 RSI: 00007ff749487bf0 RDI: 00000000000000fc
RBP: 0000000020000100 R08: 00000000000000fc R09: 0000000000000000
R10: 000000000000004a R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000627 R14: 00000000006f9448 R15: 0000000000000000

Allocated by task 15181:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:552
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3541
 reqsk_alloc include/net/request_sock.h:88 [inline]
 inet_reqsk_alloc+0xad/0x570 net/ipv4/tcp_input.c:6152
 tcp_conn_request+0x677/0x3660 net/ipv4/tcp_input.c:6250
 tcp_v6_conn_request+0x212/0x270 net/ipv6/tcp_ipv6.c:1021
 tcp_rcv_state_process+0x92a/0x4760 net/ipv4/tcp_input.c:5842
 tcp_v6_do_rcv+0x739/0x1250 net/ipv6/tcp_ipv6.c:1331
 tcp_v6_rcv+0x25a0/0x2d40 net/ipv6/tcp_ipv6.c:1521
 ip6_input_finish+0x37e/0x17a0 net/ipv6/ip6_input.c:284
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_input+0xdb/0x560 net/ipv6/ip6_input.c:327
 dst_input include/net/dst.h:449 [inline]
 ip6_rcv_finish+0x297/0x8c0 net/ipv6/ip6_input.c:71
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ipv6_rcv+0xf37/0x1fa0 net/ipv6/ip6_input.c:208
 __netif_receive_skb_core+0x1a41/0x3460 net/core/dev.c:4554
 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4619
 process_backlog+0x203/0x740 net/core/dev.c:5299
 napi_poll net/core/dev.c:5697 [inline]
 net_rx_action+0x792/0x1910 net/core/dev.c:5763
 __do_softirq+0x2d7/0xb85 kernel/softirq.c:285

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8801b8a60dc8
 which belongs to the cache request_sock_TCPv6 of size 328
The buggy address is located 216 bytes to the right of
 328-byte region [ffff8801b8a60dc8, ffff8801b8a60f10)
The buggy address belongs to the page:
page:ffffea0006e29800 count:1 mapcount:0 mapping:ffff8801b8a60000 index:0xffff8801b8a60ff6
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801b8a60000 ffff8801b8a60ff6 0000000100000009
raw: ffff8801d1869f38 ffff8801d1869f38 ffff8801d1868cc0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801b8a60e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801b8a60f00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8801b8a60f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                          ^
 ffff8801b8a61000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801b8a61080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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