==================================================================
BUG: KASAN: slab-use-after-free in __xfrm_state_delete+0x696/0xca0
Write of size 8 at addr ffff888037dc56b0 by task kworker/u8:3/5873

CPU: 0 UID: 0 PID: 5873 Comm: kworker/u8:3 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
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 print_report+0xca/0x240
 kasan_report+0x118/0x150
 __xfrm_state_delete+0x696/0xca0
 xfrm_state_flush+0x45f/0x770
 xfrm6_tunnel_net_exit+0x3c/0x100
 ops_undo_list+0x49a/0x990
 cleanup_net+0x4c5/0x800
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Allocated by task 6953:
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 xfrm_state_alloc+0x24/0x2f0
 __find_acq_core+0x8a7/0x1c00
 xfrm_find_acq+0x78/0xa0
 xfrm_alloc_userspi+0x6b3/0xc90
 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

Freed by task 10:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kmem_cache_free+0x18f/0x400
 xfrm_state_gc_task+0x52d/0x6b0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

The buggy address belongs to the object at ffff888037dc5680
 which belongs to the cache xfrm_state of size 928
The buggy address is located 48 bytes inside of
 freed 928-byte region [ffff888037dc5680, ffff888037dc5a20)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888037dc6d00 pfn:0x37dc4
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801cfc93c0 dead000000000122 0000000000000000
raw: ffff888037dc6d00 00000000800e000c 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801cfc93c0 dead000000000122 0000000000000000
head: ffff888037dc6d00 00000000800e000c 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0000df7101 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 6150, tgid 6147 (syz.2.61), ts 61746122421, free_ts 61639889386
 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/0x1410
 kmem_cache_alloc_noprof+0x283/0x3c0
 xfrm_state_alloc+0x24/0x2f0
 xfrm_state_find+0x37d4/0x5400
 xfrm_resolve_and_create_bundle+0x768/0x2f80
 xfrm_lookup_with_ifid+0x2a7/0x1a70
 xfrm_lookup_route+0x3c/0x1c0
 __ip4_datagram_connect+0x9a5/0x1270
 __ip6_datagram_connect+0x9f0/0x1150
 ip6_datagram_connect_v6_only+0x63/0xa0
 __sys_connect+0x316/0x440
page last free pid 12 tgid 12 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 stack_depot_save_flags+0x436/0x860
 ref_tracker_free+0xfe/0x7d0
 dst_destroy+0x10f/0x350
 rcu_core+0xcab/0x1770
 handle_softirqs+0x286/0x870
 do_softirq+0xec/0x180
 __local_bh_enable_ip+0x17d/0x1c0
 batadv_nc_purge_paths+0x318/0x3b0
 batadv_nc_worker+0x328/0x610
 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:
 ffff888037dc5580: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888037dc5600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888037dc5680: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff888037dc5700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888037dc5780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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