lo speed is unknown, defaulting to 1000
==================================================================
BUG: KASAN: use-after-free in xfrm_alloc_spi+0x570/0xf30
Read of size 4 at addr ffff8880296dd744 by task syz.0.2792/16226

CPU: 1 UID: 0 PID: 16226 Comm: syz.0.2792 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
 pfkey_getspi+0x7a8/0xee0
 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: 0033:0x7fc89678ebe9
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:00007fc897585038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fc8969c5fa0 RCX: 00007fc89678ebe9
RDX: 0000000000000000 RSI: 0000200000000180 RDI: 0000000000000008
RBP: 00007fc896811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc8969c6038 R14: 00007fc8969c5fa0 R15: 00007ffe859e31a8
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffffffffffffffff pfn:0x296dd
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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 15782, tgid 15778 (syz.0.2667), ts 280446523766, free_ts 281230231289
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 ___kmalloc_large_node+0x5f/0x1b0
 __kmalloc_large_node_noprof+0x18/0x90
 __kmalloc_node_track_caller_noprof+0x361/0x4e0
 kmalloc_reserve+0x136/0x290
 __alloc_skb+0x142/0x2d0
 netlink_dump+0x167/0xe90
 netlink_recvmsg+0x676/0xa30
 sock_recvmsg+0x22c/0x270
 ____sys_recvmsg+0x1c9/0x460
 ___sys_recvmsg+0x1b5/0x510
 do_recvmmsg+0x307/0x770
 __x64_sys_recvmmsg+0x190/0x240
page last free pid 23 tgid 23 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 free_large_kmalloc+0x13a/0x1f0
 skb_release_data+0x62d/0x7c0
 sk_skb_reason_drop+0x127/0x170
 skb_queue_purge_reason+0x2c8/0x360
 netlink_sock_destruct+0x2d/0x1a0
 __sk_destruct+0x89/0x660
 rcu_core+0xcab/0x1770
 handle_softirqs+0x286/0x870
 run_ksoftirqd+0x9b/0x100
 smpboot_thread_fn+0x542/0xa60
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

Memory state around the buggy address:
 ffff8880296dd600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880296dd680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880296dd700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff8880296dd780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880296dd800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
