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BUG: KASAN: use-after-free in __xfrm_state_lookup+0x6ad/0x8d0
Read of size 2 at addr ffff88802aeb45c2 by task syz.2.1668/11734

CPU: 1 UID: 0 PID: 11734 Comm: syz.2.1668 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_add+0x27d/0xc40
 xfrm_add_sa+0x35a1/0x4070
 xfrm_user_rcv_msg+0x7a3/0xab0
 netlink_rcv_skb+0x208/0x470
 xfrm_netlink_rcv+0x79/0x90
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6e4498ebe9
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:00007f6e457d4038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f6e44bb5fa0 RCX: 00007f6e4498ebe9
RDX: 0000000000000804 RSI: 0000200000000100 RDI: 0000000000000004
RBP: 00007f6e44a11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6e44bb6038 R14: 00007f6e44bb5fa0 R15: 00007ffd458da7e8
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88802aeb4000 pfn:0x2aeb4
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0000ffde08 ffffea0000ec8a08 0000000000000000
raw: ffff88802aeb4000 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 0x4429c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_ZERO|__GFP_COMP|__GFP_ACCOUNT), pid 11586, tgid 11585 (syz.2.1623), ts 183513362640, free_ts 183513443689
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 ___kmalloc_large_node+0x5f/0x1b0
 __kmalloc_large_node_noprof+0x18/0x90
 __kvmalloc_node_noprof+0x6d/0x5f0
 hash_net_create+0x358/0xfe0
 ip_set_create+0xa97/0x1940
 nfnetlink_rcv_msg+0xb4d/0x1130
 netlink_rcv_skb+0x208/0x470
 nfnetlink_rcv+0x26a/0x2520
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
page last free pid 11586 tgid 11585 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 free_large_kmalloc+0x13a/0x1f0
 hash_net4_destroy+0x6d/0x210
 ip_set_create+0x1291/0x1940
 nfnetlink_rcv_msg+0xb4d/0x1130
 netlink_rcv_skb+0x208/0x470
 nfnetlink_rcv+0x26a/0x2520
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88802aeb4480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88802aeb4500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88802aeb4580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff88802aeb4600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88802aeb4680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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