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BUG: KASAN: use-after-free in xfrm_alloc_spi+0x570/0xf30
Read of size 4 at addr ffff88810a134544 by task syz.0.11223/31757

CPU: 0 UID: 0 PID: 31757 Comm: syz.0.11223 Not tainted 6.16.0-syzkaller-06620-gae633388cae3 #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: 0033:0x7f76f138ebe9
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:00007f76f2221038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f76f15b5fa0 RCX: 00007f76f138ebe9
RDX: 0000000020000000 RSI: 0000200000000040 RDI: 0000000000000003
RBP: 00007f76f1411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f76f15b6038 R14: 00007f76f15b5fa0 R15: 00007ffc6a13c9b8
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888107d9a040 pfn:0x10a134
flags: 0x57ff00000000000(node=1|zone=2|lastcpupid=0x7ff)
raw: 057ff00000000000 ffffea0004285008 ffffea0004c23b88 0000000000000000
raw: ffff888107d9a040 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 1, migratetype Unmovable, gfp_mask 0x440dc0(GFP_KERNEL_ACCOUNT|__GFP_ZERO|__GFP_COMP), pid 5823, tgid 5823 (syz-executor), ts 450528499447, free_ts 450572547297
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 alloc_pages_noprof+0xa9/0x190
 pgd_alloc+0x44/0x570
 mm_init+0x5ef/0xef0
 copy_mm+0x123/0x4b0
 copy_process+0x1706/0x3c00
 kernel_clone+0x21e/0x840
 __x64_sys_clone+0x18b/0x1e0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 30371 tgid 30371 stack trace:
 __free_frozen_pages+0xc71/0xe70
 pagetable_dtor_free+0x2d2/0x3b0
 __mmdrop+0xb5/0x460
 exit_mm+0x1da/0x2c0
 do_exit+0x648/0x22e0
 do_group_exit+0x21c/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x21f7/0x2200
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88810a134400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88810a134480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88810a134500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff88810a134580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88810a134600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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