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BUG: KASAN: slab-out-of-bounds in __xfrm6_tunnel_spi_lookup+0x3a9/0x3b0 net/ipv6/xfrm6_tunnel.c:79
Read of size 8 at addr ffff8880623b5ea0 by task syz-executor.3/1118
CPU: 1 PID: 1118 Comm: syz-executor.3 Not tainted 5.8.0-rc5-next-20200716-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x18f/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 __xfrm6_tunnel_spi_lookup+0x3a9/0x3b0 net/ipv6/xfrm6_tunnel.c:79
 xfrm6_tunnel_spi_lookup+0x8a/0x1d0 net/ipv6/xfrm6_tunnel.c:95
 xfrmi6_rcv_tunnel+0xb9/0x100 net/xfrm/xfrm_interface.c:824
 tunnel46_rcv+0xef/0x2b0 net/ipv6/tunnel6.c:193
 ip6_protocol_deliver_rcu+0x2e8/0x1670 net/ipv6/ip6_input.c:433
 ip6_input_finish+0x7f/0x160 net/ipv6/ip6_input.c:474
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:483
 dst_input include/net/dst.h:449 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ipv6_rcv+0x28e/0x3c0 net/ipv6/ip6_input.c:307
 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5287
 __netif_receive_skb+0x27/0x1c0 net/core/dev.c:5401
 netif_receive_skb_internal net/core/dev.c:5503 [inline]
 netif_receive_skb+0x159/0x990 net/core/dev.c:5562
 tun_rx_batched.isra.0+0x460/0x720 drivers/net/tun.c:1518
 tun_get_user+0x23b2/0x35b0 drivers/net/tun.c:1972
 tun_chr_write_iter+0xba/0x151 drivers/net/tun.c:2001
 call_write_iter include/linux/fs.h:1879 [inline]
 new_sync_write+0x422/0x650 fs/read_write.c:515
 vfs_write+0x5c6/0x6f0 fs/read_write.c:595
 ksys_write+0x12d/0x250 fs/read_write.c:648
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x416661
Code: Bad RIP value.
RSP: 002b:00007ff2a25a9c60 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000050b3c0 RCX: 0000000000416661
RDX: 000000000000007a RSI: 0000000020000000 RDI: 00000000000000f0
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ff2a25aa9d0 R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000c4a R14: 00000000004ce8f4 R15: 00007ff2a25aa6d4
Allocated by task 16:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0xae/0x550 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1084 [inline]
 alloc_skb_with_frags+0x92/0x570 net/core/skbuff.c:5770
 sock_alloc_send_pskb+0x72a/0x880 net/core/sock.c:2355
 __ip_append_data+0x1595/0x31c0 net/ipv4/ip_output.c:1095
 ip_append_data net/ipv4/ip_output.c:1321 [inline]
 ip_append_data+0x114/0x1a0 net/ipv4/ip_output.c:1300
 icmp_push_reply+0x13d/0x490 net/ipv4/icmp.c:371
 __icmp_send+0xb5d/0x13d0 net/ipv4/icmp.c:740
 ipv4_send_dest_unreach net/ipv4/route.c:1221 [inline]
 ipv4_link_failure+0x5f0/0x9f0 net/ipv4/route.c:1228
 dst_link_failure include/net/dst.h:426 [inline]
 arp_error_report+0xc7/0x1c0 net/ipv4/arp.c:293
 neigh_invalidate+0x20d/0x560 net/core/neighbour.c:993
 neigh_timer_handler+0xda0/0x1150 net/core/neighbour.c:1080
 call_timer_fn+0x1ac/0x760 kernel/time/timer.c:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers.part.0+0x54c/0xa20 kernel/time/timer.c:1773
 __run_timers kernel/time/timer.c:1745 [inline]
 run_timer_softirq+0xae/0x1a0 kernel/time/timer.c:1786
 __do_softirq+0x34c/0xa60 kernel/softirq.c:292
The buggy address belongs to the object at ffff8880623b5c00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 160 bytes to the right of
 512-byte region [ffff8880623b5c00, ffff8880623b5e00)
The buggy address belongs to the page:
page:0000000080aa9131 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x623b5
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00028d44c8 ffffea0002a29988 ffff8880aa000600
raw: 0000000000000000 ffff8880623b5000 0000000100000004 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
 ffff8880623b5d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880623b5e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880623b5e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                               ^
 ffff8880623b5f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880623b5f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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