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BUG: KASAN: slab-use-after-free in hci_conn_drop+0x34/0x2a0
Write of size 4 at addr ffff888116ef0010 by task kworker/u11:6/5821

CPU: 0 UID: 0 PID: 5821 Comm: kworker/u11:6 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: hci1 hci_cmd_sync_work
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 print_report+0xba/0x230
 kasan_report+0x117/0x150
 kasan_check_range+0x264/0x2c0
 hci_conn_drop+0x34/0x2a0
 hci_cmd_sync_work+0x262/0x400
 process_scheduled_works+0xb6e/0x18c0
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Allocated by task 5821:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x31c/0x660
 __hci_conn_add+0x3c4/0x1e00
 le_conn_complete_evt+0x706/0x1430
 hci_le_enh_conn_complete_evt+0x189/0x490
 hci_event_packet+0x7af/0x12c0
 hci_rx_work+0x3ee/0x1030
 process_scheduled_works+0xb6e/0x18c0
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 ret_from_fork_asm+0x1a/0x30

Freed by task 5198:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5c/0x80
 kfree+0x1c1/0x630
 device_release+0xc4/0x1f0
 kobject_put+0x228/0x560
 hci_conn_del+0xc36/0x1230
 hci_disconn_complete_evt+0x64e/0x950
 hci_event_packet+0x805/0x12c0
 hci_rx_work+0x3ee/0x1030
 process_scheduled_works+0xb6e/0x18c0
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 ret_from_fork_asm+0x1a/0x30

The buggy address belongs to the object at ffff888116ef0000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 16 bytes inside of
 freed 8192-byte region [ffff888116ef0000, ffff888116ef2000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x116ef0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x17ff00000000040(head|node=0|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 017ff00000000040 ffff888100042280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000
head: 017ff00000000040 ffff888100042280 dead000000000100 dead000000000122
head: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000
head: 017ff00000000003 ffffea00045bbc01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 24697, tgid 24697 (syz-executor), ts 596231615666, free_ts 320264922326
 post_alloc_hook+0x231/0x280
 get_page_from_freelist+0x24dc/0x2580
 __alloc_frozen_pages_noprof+0x18d/0x380
 allocate_slab+0x77/0x660
 refill_objects+0x331/0x3c0
 __pcs_replace_empty_main+0x2e6/0x730
 __kmalloc_cache_noprof+0x392/0x660
 macvlan_common_newlink+0x5e1/0x19e0
 rtnl_newlink_create+0x329/0xb70
 rtnl_newlink+0x1666/0x1be0
 rtnetlink_rcv_msg+0x7d5/0xbe0
 netlink_rcv_skb+0x232/0x4b0
 netlink_unicast+0x80f/0x9b0
 netlink_sendmsg+0x813/0xb40
 __sys_sendto+0x672/0x710
 __x64_sys_sendto+0xde/0x100
page last free pid 5812 tgid 5812 stack trace:
 __free_frozen_pages+0xc2b/0xdb0
 __slab_free+0x263/0x2b0
 qlist_free_all+0x97/0x100
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 kmem_cache_alloc_noprof+0x2bc/0x650
 ptlock_alloc+0x20/0x70
 pte_alloc_one+0x7a/0x370
 __pte_alloc+0x25/0x1a0
 copy_pmd_range+0x77d2/0x8050
 copy_page_range+0xbe8/0x11f0
 dup_mmap+0xf40/0x1d90
 copy_mm+0x13b/0x4a0
 copy_process+0x18b6/0x3cd0
 kernel_clone+0x248/0x8e0
 __x64_sys_clone+0x1b6/0x230

Memory state around the buggy address:
 ffff888116eeff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888116eeff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888116ef0000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff888116ef0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888116ef0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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