==================================================================
BUG: KASAN: slab-use-after-free in __mutex_lock+0x738/0xe80
Read of size 8 at addr ffff8881265f40a0 by task khidpd_15c25886/6300

CPU: 1 UID: 0 PID: 6300 Comm: khidpd_15c25886 Not tainted 6.16.0-rc3-syzkaller-00159-g223e2288f4b8 #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+0xd2/0x2b0
 kasan_report+0x118/0x150
 __mutex_lock+0x738/0xe80
 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 6113:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_noprof+0x27a/0x4f0
 hci_alloc_dev_priv+0x28/0x2040
 vhci_create_device+0x120/0x6e0
 vhci_write+0x3ce/0x4a0
 vfs_write+0x54b/0xa90
 ksys_write+0x145/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6113:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x62/0x70
 kfree+0x18e/0x440
 bt_host_release+0x82/0x90
 device_release+0x9c/0x1c0
 kobject_put+0x22b/0x480
 vhci_release+0x88/0xd0
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 do_exit+0x6b5/0x22e0
 do_group_exit+0x21c/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x21ba/0x21c0
 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+0xbd9/0xfe0
 queue_work_on+0x181/0x270
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 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+0xcfc/0xfe0
 call_timer_fn+0x17e/0x5f0
 __run_timer_base+0x646/0x860
 run_timer_softirq+0xb7/0x180
 handle_softirqs+0x286/0x870
 run_ksoftirqd+0x9b/0x100
 smpboot_thread_fn+0x542/0xa60
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

The buggy address belongs to the object at ffff8881265f4000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 160 bytes inside of
 freed 8192-byte region [ffff8881265f4000, ffff8881265f6000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8881265f0000 pfn:0x1265f0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000240(workingset|head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000240 ffff88801a442280 ffffea00049dca10 ffffea0004995e10
raw: ffff8881265f0000 0000000000020001 00000000f5000000 0000000000000000
head: 057ff00000000240 ffff88801a442280 ffffea00049dca10 ffffea0004995e10
head: ffff8881265f0000 0000000000020001 00000000f5000000 0000000000000000
head: 057ff00000000003 ffffea0004997c01 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 5959, tgid 5959 (syz-executor), ts 69247119014, free_ts 69239869031
 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/0x3b0
 ___slab_alloc+0xbfc/0x1480
 __kmalloc_noprof+0x305/0x4f0
 ops_init+0x7b/0x5c0
 setup_net+0x219/0x4b0
 copy_net_ns+0x31b/0x4d0
 create_new_namespaces+0x3f3/0x720
 unshare_nsproxy_namespaces+0x11c/0x170
 ksys_unshare+0x4c8/0x8c0
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5959 tgid 5959 stack trace:
 __free_frozen_pages+0xc71/0xe70
 __put_partials+0x161/0x1c0
 put_cpu_partial+0x17c/0x250
 __slab_free+0x2f7/0x400
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 __kmalloc_cache_noprof+0x1be/0x3d0
 kset_create_and_add+0x5a/0x170
 netdev_register_kobject+0x180/0x2f0
 register_netdevice+0x126c/0x1ae0
 register_netdev+0x40/0x60
 ip6_tnl_init_net+0x259/0x3b0
 ops_init+0x35c/0x5c0
 setup_net+0x219/0x4b0
 copy_net_ns+0x31b/0x4d0

Memory state around the buggy address:
 ffff8881265f3f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881265f4000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881265f4080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff8881265f4100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881265f4180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
