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BUG: KASAN: use-after-free in __xfrm_state_delete+0x696/0xca0
Write of size 8 at addr ffff88812123c4b0 by task syz.2.636/8329

CPU: 0 UID: 0 PID: 8329 Comm: syz.2.636 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:
 <IRQ>
 dump_stack_lvl+0x189/0x250
 print_report+0xca/0x240
 kasan_report+0x118/0x150
 __xfrm_state_delete+0x696/0xca0
 xfrm_timer_handler+0x18f/0xa00
 __hrtimer_run_queues+0x52c/0xc60
 hrtimer_run_softirq+0x187/0x2b0
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:lockdep_unregister_key+0x2c5/0x310
Code: 65 48 8b 05 4d 1d 03 11 48 3b 44 24 10 0f 84 26 fe ff ff e8 0d a4 dc 09 e8 38 a5 dc 09 41 f7 c7 00 02 00 00 74 bd fb 40 84 ed <75> bc eb cd 90 0f 0b 90 e9 19 ff ff ff 90 0f 0b 90 e9 2a ff ff ff
RSP: 0018:ffffc90007fc7998 EFLAGS: 00000202
RAX: 1c0e01e145dd1c00 RBX: 0000000000000001 RCX: 1c0e01e145dd1c00
RDX: ffffffff93647338 RSI: ffffffff8d9cd7dc RDI: ffffffff8be33c00
RBP: ffff88802ff50201 R08: 0000000000000000 R09: ffffffff81aa9548
R10: dffffc0000000000 R11: fffffbfff1f474c7 R12: 0000000000000000
R13: 0000000000001000 R14: 0000000000000001 R15: 0000000000000206
 __qdisc_destroy+0x166/0x420
 dev_shutdown+0x93/0x440
 unregister_netdevice_many_notify+0xe0f/0x1ff0
 unregister_netdevice_queue+0x33c/0x380
 __tun_detach+0xda4/0x1560
 tun_chr_close+0x10a/0x1c0
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xec/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd351d8ec29
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:00007ffd690160d8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 000000000001d139 RCX: 00007fd351d8ec29
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fd351fd7da0 R08: 0000000000000001 R09: 00000018690163cf
R10: 0000001b31720000 R11: 0000000000000246 R12: 00007fd351fd5fac
R13: 00007fd351fd5fa0 R14: ffffffffffffffff R15: 00007ffd690161f0
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88812123fb80 pfn:0x12123c
flags: 0x57ff00000000000(node=1|zone=2|lastcpupid=0x7ff)
raw: 057ff00000000000 ffffea0004842408 ffffea0004459808 0000000000000000
raw: ffff88812123fb80 0000000000120000 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 8155, tgid 8154 (syz.1.601), ts 114754968992, free_ts 118388295877
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 allocate_slab+0x8a/0x370
 ___slab_alloc+0xbeb/0x1420
 kmem_cache_alloc_node_noprof+0x280/0x3c0
 kmalloc_reserve+0xbd/0x290
 __alloc_skb+0x142/0x2d0
 alloc_skb_with_frags+0xca/0x890
 sock_alloc_send_pskb+0x857/0x990
 __ip_append_data+0x2ce8/0x40c0
 ip_make_skb+0x1de/0x3f0
 udp_sendmsg+0x1925/0x2170
 __sock_sendmsg+0x19c/0x270
 ____sys_sendmsg+0x52d/0x830
page last free pid 8298 tgid 8293 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 __put_partials+0x156/0x1a0
 put_cpu_partial+0x17c/0x250
 __slab_free+0x2d5/0x3c0
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 kmem_cache_alloc_node_noprof+0x1bb/0x3c0
 __alloc_skb+0x112/0x2d0
 alloc_skb_with_frags+0xca/0x890
 sock_alloc_send_pskb+0x857/0x990
 llc_ui_sendmsg+0x477/0xdd0
 __sock_sendmsg+0x21c/0x270
 sock_sendmsg+0x158/0x230
 splice_to_socket+0x8ff/0xf10
 direct_splice_actor+0x101/0x160

Memory state around the buggy address:
 ffff88812123c380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812123c400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88812123c480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                     ^
 ffff88812123c500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812123c580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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