netlink: 'syz.1.1756': attribute type 29 has an invalid length.
netlink: 500 bytes leftover after parsing attributes in process `syz.1.1756'.
==================================================================
BUG: KASAN: use-after-free in xfrm_alloc_spi+0x570/0xf30
Read of size 4 at addr ffff888111de76c4 by task syz.1.1756/12782

CPU: 1 UID: 0 PID: 12782 Comm: syz.1.1756 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_alloc_spi+0x570/0xf30
 xfrm_alloc_userspi+0x70b/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
RIP: 0033:0x7f54b678ebe9
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:00007f54b75fe038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f54b69c6090 RCX: 00007f54b678ebe9
RDX: 0000000000000000 RSI: 0000200000000840 RDI: 0000000000000004
RBP: 00007f54b6811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f54b69c6128 R14: 00007f54b69c6090 R15: 00007ffe37e3a8a8
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111de7
flags: 0x57ff00000000000(node=1|zone=2|lastcpupid=0x7ff)
raw: 057ff00000000000 0000000000000000 ffffea00044779c8 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 12527, tgid 12526 (syz.2.1682), ts 220286074259, free_ts 221112045817
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 __alloc_pages_noprof+0xa/0x30
 __page_frag_cache_refill+0x3f/0x140
 __page_frag_alloc_align+0x7a/0x4c0
 rxrpc_alloc_data_txbuf+0x192/0x640
 rxrpc_send_data+0xf3e/0x2160
 rxrpc_do_sendmsg+0x1098/0x1220
 __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
page last free pid 12528 tgid 12528 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 rxrpc_put_txbuf+0x15a/0x2c0
 rxrpc_destroy_call+0xc1/0x420
 rxrpc_io_thread+0x2f35/0x35e0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

Memory state around the buggy address:
 ffff888111de7580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888111de7600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888111de7680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff888111de7700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888111de7780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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