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BUG: KASAN: use-after-free in __xfrm_state_lookup+0x6ad/0x8d0
Read of size 2 at addr ffff88810a44cec2 by task syz.0.3445/18981

CPU: 0 UID: 0 PID: 18981 Comm: syz.0.3445 Not tainted 6.16.0-syzkaller-12063-g37816488247d-dirty #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_state_lookup+0x6ad/0x8d0
 xfrm_state_add+0x27d/0xc40
 pfkey_add+0x1edd/0x2e00
 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: 0033:0x7f3de358ebe9
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:00007f3de44d3038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f3de37b5fa0 RCX: 00007f3de358ebe9
RDX: 0000000000000000 RSI: 00002000000001c0 RDI: 0000000000000008
RBP: 00007f3de3611e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3de37b6038 R14: 00007f3de37b5fa0 R15: 00007fff1c6a4458
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x334 pfn:0x10a44c
flags: 0x57ff00000000000(node=1|zone=2|lastcpupid=0x7ff)
page_type: f0(buddy)
raw: 057ff00000000000 ffffea0004294f08 ffffea0004822008 0000000000000000
raw: 0000000000000334 0000000000000002 00000000f0000000 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 0x140cc2(GFP_HIGHUSER|__GFP_COMP), pid 18310, tgid 18308 (syz.2.3240), ts 431856727023, free_ts 431907180101
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 folio_alloc_mpol_noprof+0x39/0x70
 shmem_alloc_and_add_folio+0x447/0xf60
 shmem_get_folio_gfp+0x59d/0x1660
 shmem_fault+0x179/0x390
 __do_fault+0x138/0x390
 __handle_mm_fault+0x1847/0x5440
 handle_mm_fault+0x40a/0x8e0
 __get_user_pages+0x1699/0x2ce0
 __gup_longterm_locked+0x7fb/0x1660
 gup_fast_fallback+0x1e6a/0x2010
 rds_cmsg_rdma_args+0x8f4/0x1240
 rds_cmsg_send+0x33d/0x5c0
page last free pid 18312 tgid 18308 stack trace:
 free_unref_folios+0xdbd/0x1520
 folios_put_refs+0x559/0x640
 shmem_undo_range+0x49e/0x14b0
 shmem_evict_inode+0x272/0xa70
 evict+0x504/0x9c0
 __dentry_kill+0x209/0x660
 dput+0x19f/0x2b0
 __fput+0x68e/0xa70
 task_work_run+0x1d4/0x260
 do_exit+0x6b5/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1286/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88810a44cd80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88810a44ce00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88810a44ce80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff88810a44cf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88810a44cf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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