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BUG: KASAN: slab-use-after-free in __xfrm_state_lookup.isra.0+0x752/0x870
Read of size 2 at addr ffff88801a684142 by task syz-executor.1/25087

CPU: 1 UID: 0 PID: 25087 Comm: syz-executor.1 Not tainted 6.16.0-rc6-next-20250717 #1 PREEMPT(voluntary) 
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xca/0x120
 print_report+0xcb/0x5f0
 kasan_report+0xca/0x100
 __xfrm_state_lookup.isra.0+0x752/0x870
 xfrm_state_lookup+0xf7/0x2a0
 xfrm_add_sa_expire+0x1ae/0x4a0
 xfrm_user_rcv_msg+0x459/0xa00
 netlink_rcv_skb+0x147/0x430
 xfrm_netlink_rcv+0x74/0x90
 netlink_unicast+0x58d/0x850
 netlink_sendmsg+0x8ac/0xd80
 ____sys_sendmsg+0xa67/0xc20
 ___sys_sendmsg+0x10f/0x1b0
 __sys_sendmsg+0x150/0x200
 do_syscall_64+0xbf/0x360
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa0fd68cb19
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa0fac02188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fa0fd79ff60 RCX: 00007fa0fd68cb19
RDX: 0000000020000000 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 00007fa0fd6e6f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc3be5299f R14: 00007fa0fac02300 R15: 0000000000022000
 </TASK>

Allocated by task 5863:
 kasan_save_stack+0x24/0x50
 kasan_save_track+0x14/0x30
 __kasan_slab_alloc+0x59/0x70
 kmem_cache_alloc_noprof+0x13c/0x3d0
 xfrm_state_alloc+0x25/0x600
 __find_acq_core+0x9c8/0x27a0
 xfrm_find_acq+0x7f/0xb0
 xfrm_alloc_userspi+0x589/0xbb0
 xfrm_user_rcv_msg+0x459/0xa00
 netlink_rcv_skb+0x147/0x430
 xfrm_netlink_rcv+0x74/0x90
 netlink_unicast+0x58d/0x850
 netlink_sendmsg+0x8ac/0xd80
 ____sys_sendmsg+0xa67/0xc20
 ___sys_sendmsg+0x10f/0x1b0
 __sys_sendmsg+0x150/0x200
 do_syscall_64+0xbf/0x360
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5769:
 kasan_save_stack+0x24/0x50
 kasan_save_track+0x14/0x30
 kasan_save_free_info+0x3a/0x60
 __kasan_slab_free+0x38/0x50
 kmem_cache_free+0x2a1/0x460
 xfrm_state_gc_task+0x107/0x740
 process_one_work+0x8e1/0x19c0
 worker_thread+0x67e/0xe90
 kthread+0x3c8/0x740
 ret_from_fork+0x34b/0x430
 ret_from_fork_asm+0x1a/0x30

The buggy address belongs to the object at ffff88801a684000
 which belongs to the cache xfrm_state of size 920
The buggy address is located 322 bytes inside of
 freed 920-byte region [ffff88801a684000, ffff88801a684398)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88801a684440 pfn:0x1a684
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x100000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0100000000000040 ffff88800a7eb780 dead000000000122 0000000000000000
raw: ffff88801a684440 00000000800f000d 00000000f5000000 0000000000000000
head: 0100000000000040 ffff88800a7eb780 dead000000000122 0000000000000000
head: ffff88801a684440 00000000800f000d 00000000f5000000 0000000000000000
head: 0100000000000002 ffffea000069a101 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88801a684000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88801a684080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88801a684100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff88801a684180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88801a684200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
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tmpfs: Unknown parameter 'Nr@i§g'node)sJA'
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tmpfs: Unknown parameter 'Nr@i§g'node)sJA'