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BUG: KFENCE: use-after-free read in __xfrm_state_insert+0x855/0x1450

Use-after-free read at 0xffff8881365e6f30 (in kfence-#242):
 __xfrm_state_insert+0x855/0x1450
 xfrm_state_insert+0x54/0x60
 ipcomp6_init_state+0x655/0x900
 __xfrm_init_state+0xa76/0x13f0
 xfrm_init_state+0x18/0xa0
 pfkey_add+0x1d38/0x2e00
 pfkey_sendmsg+0xbfe/0x1090
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x52d/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __sys_sendmmsg+0x227/0x430
 __x64_sys_sendmmsg+0xa0/0xc0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

kfence-#242: 0xffff8881365e6000-0xffff8881365e60ef, size=240, cache=skbuff_head_cache

allocated by task 5284 on cpu 0 at 165.413063s (2.636575s ago):
 __alloc_skb+0x112/0x2d0
 alloc_skb_with_frags+0xca/0x890
 sock_alloc_send_pskb+0x857/0x990
 unix_dgram_sendmsg+0x461/0x1850
 __sock_sendmsg+0x21c/0x270
 __sys_sendto+0x3bd/0x520
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

freed by task 5277 on cpu 0 at 165.413251s (2.657052s ago):
 __unix_dgram_recvmsg+0x9f9/0xd60
 sock_recvmsg+0x22c/0x270
 sock_read_iter+0x231/0x2f0
 vfs_read+0x55a/0xa30
 ksys_read+0x145/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 1 UID: 0 PID: 12390 Comm: syz.0.1899 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_insert+0x855/0x1450
Code: d8 0f 94 c1 08 c1 74 0a e8 a8 d3 9c f7 e9 aa 00 00 00 4d 8d ac 24 30 03 00 00 4d 89 ee 49 c1 ee 03 41 0f b6 04 1e 84 c0 75 48 <41> 0f b6 6d 00 83 e5 0c bf 08 00 00 00 89 ee e8 77 d6 9c f7 83 fd
RSP: 0018:ffffc900030ef3a0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffff888108d43980 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 0000000000000004 R08: dffffc0000000000 R09: 0000000000000002
R10: 000000000000000a R11: 0000000000000002 R12: ffff8881365e6c00
R13: ffff8881365e6f30 R14: 1ffff11026cbcde6 R15: 0000000000000004
FS:  00007f4a0abf66c0(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8881365e6f30 CR3: 00000001269c2000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 xfrm_state_insert+0x54/0x60
 ipcomp6_init_state+0x655/0x900
 __xfrm_init_state+0xa76/0x13f0
 xfrm_init_state+0x18/0xa0
 pfkey_add+0x1d38/0x2e00
 pfkey_sendmsg+0xbfe/0x1090
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x52d/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __sys_sendmmsg+0x227/0x430
 __x64_sys_sendmmsg+0xa0/0xc0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4a0c98ec29
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:00007f4a0abf6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f4a0cbd5fa0 RCX: 00007f4a0c98ec29
RDX: 000000000400008a RSI: 0000200000000180 RDI: 0000000000000004
RBP: 00007f4a0ca11e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4a0cbd6038 R14: 00007f4a0cbd5fa0 R15: 00007ffc96b4d2e8
 </TASK>
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