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BUG: KASAN: use-after-free in __xfrm_state_lookup+0x6ad/0x8d0
Read of size 2 at addr ffff888031f45c42 by task syz.1.416/7605

CPU: 0 UID: 0 PID: 7605 Comm: syz.1.416 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: 0033:0x7fd335d8ebe9
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:00007fd336b17038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fd335fb6090 RCX: 00007fd335d8ebe9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000003
RBP: 00007fd335e11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd335fb6128 R14: 00007fd335fb6090 R15: 00007fffa3392b18
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffffffffffffffff pfn:0x31f45
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 7238, tgid 7233 (syz.0.318), ts 70196654663, free_ts 78147890617
 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
 udp_sendmsg+0x142e/0x2170
 __sock_sendmsg+0x19c/0x270
 ____sys_sendmsg+0x52d/0x830
 ___sys_sendmsg+0x21f/0x2a0
page last free pid 7596 tgid 7592 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
 __kmalloc_noprof+0x224/0x4f0
 fib6_info_alloc+0x30/0xf0
 ip6_route_info_create+0x142/0x860
 ip6_route_add+0x49/0x1b0
 addrconf_add_dev+0x24f/0x340
 addrconf_init_auto_addrs+0x57c/0xa30
 addrconf_notify+0xacc/0x1010
 notifier_call_chain+0x1b6/0x3e0
 netif_open+0xfd/0x170
 dev_open+0x125/0x260
 team_add_slave+0xab9/0x26f0

Memory state around the buggy address:
 ffff888031f45b00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888031f45b80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888031f45c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff888031f45c80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888031f45d00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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