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BUG: KASAN: use-after-free in xfrm_alloc_spi+0x570/0xf30
Read of size 4 at addr ffff88802842edc4 by task syz.2.9317/27243

CPU: 1 UID: 0 PID: 27243 Comm: syz.2.9317 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: 0033:0x7fdf4698ebe9
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:00007fdf478bd038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fdf46bc6090 RCX: 00007fdf4698ebe9
RDX: 000000000400c8c0 RSI: 0000200000000200 RDI: 0000000000000004
RBP: 00007fdf46a11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdf46bc6128 R14: 00007fdf46bc6090 R15: 00007ffe1dd7c0b8
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x200000062 pfn:0x2842e
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000200000062 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x140dc2(GFP_HIGHUSER|__GFP_ZERO|__GFP_COMP), pid 26586, tgid 26585 (syz.2.9042), ts 443210126757, free_ts 443301815797
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 vma_alloc_folio_noprof+0xe4/0x200
 folio_prealloc+0x30/0x180
 __handle_mm_fault+0x2ab9/0x5440
 handle_mm_fault+0x40a/0x8e0
 __get_user_pages+0x1699/0x2ce0
 __gup_longterm_locked+0x3dc/0x1660
 pin_user_pages+0x9e/0xd0
 xdp_umem_pin_pages+0x117/0x340
 xdp_umem_create+0x677/0x8e0
 xsk_setsockopt+0x7b0/0x8d0
 do_sock_setsockopt+0x17c/0x1b0
 __x64_sys_setsockopt+0x13f/0x1b0
page last free pid 792 tgid 792 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 __folio_put+0x21b/0x2c0
 unpin_user_pages_dirty_lock+0x395/0x510
 xdp_umem_release+0xdc/0x220
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

Memory state around the buggy address:
 ffff88802842ec80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88802842ed00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88802842ed80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff88802842ee00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88802842ee80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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