==================================================================
BUG: KASAN: slab-use-after-free in __mutex_lock+0x801/0x1350
Read of size 8 at addr ffff88811f8740a0 by task khidpd_15c25886/29519

CPU: 0 UID: 0 PID: 29519 Comm: khidpd_15c25886 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:
 <TASK>
 dump_stack_lvl+0x189/0x250
 print_report+0xca/0x240
 kasan_report+0x118/0x150
 __mutex_lock+0x801/0x1350
 l2cap_unregister_user+0x6a/0x1b0
 hidp_session_thread+0x3c9/0x410
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Allocated by task 28489:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_noprof+0x41d/0x800
 hci_alloc_dev_priv+0x28/0x2060
 vhci_create_device+0x120/0x650
 vhci_write+0x3ce/0x4a0
 vfs_write+0x5c9/0xb30
 ksys_write+0x145/0x250
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 28633:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5c/0x80
 kfree+0x19a/0x6d0
 bt_host_release+0x82/0x90
 device_release+0x9c/0x1c0
 kobject_put+0x22b/0x480
 vhci_release+0x15a/0x1a0
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 do_exit+0x6b5/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1285/0x1340
 arch_do_signal_or_restart+0xa0/0x790
 exit_to_user_mode_loop+0x72/0x130
 do_syscall_64+0x2bd/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60
 kasan_record_aux_stack+0xbd/0xd0
 insert_work+0x3d/0x330
 __queue_work+0xcd2/0xfb0
 queue_work_on+0x181/0x270
 hci_cmd_sync_submit+0x285/0x2b0
 le_conn_complete_evt+0xd8d/0x1500
 hci_le_conn_complete_evt+0x187/0x450
 hci_event_packet+0x78f/0x1200
 hci_rx_work+0x46a/0xe80
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 ret_from_fork_asm+0x1a/0x30

Second to last potentially related work creation:
 kasan_save_stack+0x3e/0x60
 kasan_record_aux_stack+0xbd/0xd0
 insert_work+0x3d/0x330
 __queue_work+0xbaf/0xfb0
 queue_work_on+0x181/0x270
 l2cap_connect_cfm+0xd3b/0x1040
 hci_connect_cfm+0x95/0x140
 le_conn_complete_evt+0xfb8/0x1500
 hci_le_conn_complete_evt+0x187/0x450
 hci_event_packet+0x78f/0x1200
 hci_rx_work+0x46a/0xe80
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 ret_from_fork_asm+0x1a/0x30

The buggy address belongs to the object at ffff88811f874000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 160 bytes inside of
 freed 8192-byte region [ffff88811f874000, ffff88811f876000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11f870
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x17ff00000000040(head|node=0|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 017ff00000000040 ffff888100042280 ffffea0004574e00 0000000000000005
raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 017ff00000000040 ffff888100042280 ffffea0004574e00 0000000000000005
head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 017ff00000000003 ffffea00047e1c01 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 0x528c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP), pid 24522, tgid 24522 (syz-executor), ts 627807032570, free_ts 626834254771
 post_alloc_hook+0x234/0x290
 get_page_from_freelist+0x2365/0x2440
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 allocate_slab+0x96/0x350
 ___slab_alloc+0xf56/0x1990
 __slab_alloc+0x65/0x100
 __kvmalloc_node_noprof+0x6ba/0x910
 pfifo_fast_init+0x242/0x6c0
 qdisc_create_dflt+0x13b/0x4e0
 dev_activate+0x378/0x1150
 __dev_open+0x69c/0x880
 __dev_change_flags+0x1ea/0x6d0
 netif_change_flags+0x88/0x1a0
 do_setlink+0xc55/0x41c0
 rtnl_newlink+0x1619/0x1c80
page last free pid 24598 tgid 24597 stack trace:
 __free_frozen_pages+0xbc8/0xd30
 __slab_free+0x2e7/0x390
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 kmem_cache_alloc_noprof+0x37d/0x700
 getname_flags+0xb8/0x540
 do_sys_openat2+0xbc/0x1c0
 __x64_sys_open+0x11e/0x150
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88811f873f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88811f874000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88811f874080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff88811f874100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88811f874180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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