==================================================================
BUG: KASAN: slab-use-after-free in __mutex_lock+0x801/0x1350
Read of size 8 at addr ffff8881101280a0 by task khidpd_15c25886/6354

CPU: 1 UID: 0 PID: 6354 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+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Allocated by task 5853:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_noprof+0x27a/0x4f0
 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/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5853:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kfree+0x18e/0x440
 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
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x21f7/0x2200
 do_syscall_64+0xfa/0x3b0
 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
 l2cap_chan_send+0x1110/0x2790
 l2cap_sock_sendmsg+0x32e/0x4a0
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x52d/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __sys_sendmmsg+0x227/0x430
 __x64_sys_sendmmsg+0xa0/0xc0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Second to 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
 l2cap_chan_send+0x1110/0x2790
 l2cap_sock_sendmsg+0x32e/0x4a0
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x52d/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __sys_sendmmsg+0x227/0x430
 __x64_sys_sendmmsg+0xa0/0xc0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888110128000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 160 bytes inside of
 freed 8192-byte region [ffff888110128000, ffff88811012a000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x110128
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff88801a442280 0000000000000000 0000000000000001
raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff88801a442280 0000000000000000 0000000000000001
head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 057ff00000000003 ffffea0004404a01 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5593, tgid 5593 (dhcpcd), ts 39894074584, free_ts 39842896526
 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
 __kmalloc_node_track_caller_noprof+0x2f8/0x4e0
 kmalloc_reserve+0x136/0x290
 __alloc_skb+0x142/0x2d0
 netlink_dump+0x167/0xe90
 netlink_recvmsg+0x676/0xa30
 sock_recvmsg+0x22c/0x270
 ____sys_recvmsg+0x1c9/0x460
 ___sys_recvmsg+0x1b5/0x510
 __x64_sys_recvmsg+0x198/0x260
 do_syscall_64+0xfa/0x3b0
page last free pid 5687 tgid 5687 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_noprof+0x1c1/0x3c0
 getname_flags+0xb8/0x540
 do_sys_openat2+0xbc/0x1c0
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888110127f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888110128000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888110128080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff888110128100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888110128180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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