syzkaller1: entered promiscuous mode
syzkaller1: entered allmulticast mode
==================================================================
BUG: KASAN: use-after-free in __xfrm_state_lookup+0x6ad/0x8d0
Read of size 2 at addr ffff88803ae95c42 by task syz.1.2165/14078

CPU: 1 UID: 0 PID: 14078 Comm: syz.1.2165 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 print_report+0xca/0x240
 kasan_report+0x118/0x150
 __xfrm_state_lookup+0x6ad/0x8d0
 xfrm_state_lookup+0x11e/0x1e0
 xfrmi4_err+0x3b7/0x7d0
 xfrm4_ah_err+0x93/0x1e0
 icmp_redirect+0x1a5/0x310
 icmp_rcv+0xd15/0x1270
 ip_protocol_deliver_rcu+0x2e0/0x440
 ip_local_deliver_finish+0x3bb/0x6f0
 NF_HOOK+0x30c/0x3a0
 NF_HOOK+0x30c/0x3a0
 __netif_receive_skb+0x143/0x380
 netif_receive_skb+0x1cb/0x790
 tun_rx_batched+0x1b9/0x730
 tun_get_user+0x2aa2/0x3e20
 tun_chr_write_iter+0x113/0x200
 vfs_write+0x5c9/0xb30
 ksys_write+0x145/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe80f58ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe8104c5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fe80f7b5fa0 RCX: 00007fe80f58ebe9
RDX: 000000000000fdef RSI: 0000200000000100 RDI: 0000000000000006
RBP: 00007fe80f611e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe80f7b6038 R14: 00007fe80f7b5fa0 R15: 00007ffe181580f8
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffffffffffffffff pfn:0x3ae95
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 00000000ffffffff 0000000000000000
raw: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 6130, tgid 6129 (syz.0.59), ts 50828039289, free_ts 177621344889
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 allocate_slab+0x8a/0x370
 ___slab_alloc+0xbeb/0x1410
 kmem_cache_alloc_noprof+0x283/0x3c0
 xfrm_state_alloc+0x24/0x2f0
 xfrm_state_find+0x37d4/0x5400
 xfrm_resolve_and_create_bundle+0x768/0x2f80
 xfrm_lookup_with_ifid+0x2a7/0x1a70
 xfrm_lookup_route+0x3c/0x1c0
 __ip4_datagram_connect+0x9a5/0x1270
 __ip6_datagram_connect+0x9f0/0x1150
 ip6_datagram_connect_v6_only+0x63/0xa0
 __sys_connect+0x316/0x440
page last free pid 5837 tgid 5837 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 __slab_free+0x303/0x3c0
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 getname_flags+0xb8/0x540
 user_path_at+0x24/0x60
 __x64_sys_umount+0xee/0x160
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88803ae95b00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88803ae95b80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88803ae95c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff88803ae95c80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88803ae95d00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
