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BUG: KFENCE: use-after-free read in __xfrm_state_lookup+0x319/0x8d0

Use-after-free read at 0xffff8881365ea142 (in kfence-#244):
 __xfrm_state_lookup+0x319/0x8d0
 xfrm_state_lookup+0x11e/0x1e0
 ipcomp4_init_state+0x205/0xb20
 __xfrm_init_state+0xa76/0x13f0
 xfrm_add_sa+0x2f5b/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

kfence-#244: 0xffff8881365ea000-0xffff8881365ea39f, size=928, cache=xfrm_state

allocated by task 9816 on cpu 1 at 189.075455s (35.615239s ago):
 xfrm_state_alloc+0x24/0x2f0
 __find_acq_core+0x8a7/0x1c00
 xfrm_find_acq+0x78/0xa0
 xfrm_alloc_userspi+0x6b3/0xc90
 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 47 on cpu 1 at 219.098312s (5.623425s ago):
 xfrm_state_gc_task+0x52d/0x6b0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

CPU: 0 UID: 0 PID: 11047 Comm: syz.0.2152 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
RIP: 0010:__xfrm_state_lookup+0x319/0x8d0
Code: 30 48 89 4c 24 38 48 c1 e9 03 48 89 4c 24 50 4c 8d b3 42 01 00 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 7c 03 00 00 <45> 0f b7 36 44 89 f7 44 89 ee e8 a8 82 9f f7 66 45 39 ee 0f 85 2f
RSP: 0018:ffffc9000478f020 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8881365ea000 RCX: 1ffff11004799db7
RDX: ffff88802438b980 RSI: 0000000000000002 RDI: 000000000000000a
RBP: ffffc9000478f118 R08: ffff88802438b980 R09: 0000000000000002
R10: 000000000000000a R11: 0000000000000002 R12: dffffc0000000000
R13: 0000000000000002 R14: ffff8881365ea142 R15: 000000000100007f
FS:  00007f537ff246c0(0000) GS:ffff8880b861c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8881365ea142 CR3: 0000000033c98000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 xfrm_state_lookup+0x11e/0x1e0
 ipcomp4_init_state+0x205/0xb20
 __xfrm_init_state+0xa76/0x13f0
 xfrm_add_sa+0x2f5b/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: 0033:0x7f537f18ebe9
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:00007f537ff24038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f537f3c5fa0 RCX: 00007f537f18ebe9
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000005
RBP: 00007f537f211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f537f3c6038 R14: 00007f537f3c5fa0 R15: 00007ffefb8935b8
 </TASK>
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