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BUG: KASAN: slab-use-after-free in __xfrm_state_lookup+0x6ad/0x8d0
Read of size 2 at addr ffff88811bc20a42 by task syz.1.6771/28761

CPU: 1 UID: 0 PID: 28761 Comm: syz.1.6771 Not tainted 6.16.0-syzkaller-06574-gd9104cec3e8f-dirty #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
 pfkey_delete+0x357/0x6d0
 pfkey_sendmsg+0xbfe/0x1090
 __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: 0033:0x7f600e78ebe9
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:00007f600f52c038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f600e9b5fa0 RCX: 00007f600e78ebe9
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000006
RBP: 00007f600e811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f600e9b6038 R14: 00007f600e9b5fa0 R15: 00007ffd20bf1838
 </TASK>

Allocated by task 28291:
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 xfrm_state_alloc+0x24/0x2f0
 xfrm_add_acquire+0xf7/0xb20
 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

Freed by task 28291:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x62/0x70
 kmem_cache_free+0x18f/0x400
 xfrm_add_acquire+0x9cc/0xb20
 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

The buggy address belongs to the object at ffff88811bc20900
 which belongs to the cache xfrm_state of size 928
The buggy address is located 322 bytes inside of
 freed 928-byte region [ffff88811bc20900, ffff88811bc20ca0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88811bc20000 pfn:0x11bc20
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff88801af37640 dead000000000122 0000000000000000
raw: ffff88811bc20000 00000000800e000b 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff88801af37640 dead000000000122 0000000000000000
head: ffff88811bc20000 00000000800e000b 00000000f5000000 0000000000000000
head: 057ff00000000002 ffffea00046f0801 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 22438, tgid 22428 (syz.1.4890), ts 309170496642, free_ts 309168654073
 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/0x3b0
 ___slab_alloc+0xbfc/0x1480
 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
 sctp_v6_get_dst+0x7cc/0x1bc0
 sctp_transport_pmtu+0x132/0x5d0
 sctp_transport_route+0x186/0x2f0
 sctp_packet_config+0x478/0xd90
page last free pid 22438 tgid 22428 stack trace:
 __free_frozen_pages+0xc71/0xe70
 stack_depot_save_flags+0x445/0x900
 kasan_save_track+0x4f/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_node_track_caller_noprof+0x271/0x4e0
 kmalloc_reserve+0x136/0x290
 __alloc_skb+0x142/0x2d0
 xfrm_send_acquire+0x154/0xee0
 km_query+0x11c/0x210
 xfrm_state_find+0x3bca/0x5400
 xfrm_resolve_and_create_bundle+0x768/0x2f80
 xfrm_lookup_with_ifid+0x2a7/0x1a70
 xfrm_lookup_route+0x3c/0x1c0
 sctp_v6_get_dst+0xffa/0x1bc0
 sctp_transport_route+0x118/0x2f0
 sctp_assoc_add_peer+0x657/0x13b0

Memory state around the buggy address:
 ffff88811bc20900: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88811bc20980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88811bc20a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff88811bc20a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88811bc20b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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