==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:112 [inline]
BUG: KASAN: slab-use-after-free in atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline]
BUG: KASAN: slab-use-after-free in hci_conn_drop+0x34/0x2a0 include/net/bluetooth/hci_core.h:1690
Write of size 4 at addr ffff8880360c8010 by task kworker/u5:0/45

CPU: 0 UID: 0 PID: 45 Comm: kworker/u5:0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: hci0 hci_cmd_sync_work
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xba/0x230 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200
 instrument_atomic_read_write include/linux/instrumented.h:112 [inline]
 atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline]
 hci_conn_drop+0x34/0x2a0 include/net/bluetooth/hci_core.h:1690
 hci_cmd_sync_work+0x262/0x400 net/bluetooth/hci_sync.c:334
 process_one_work kernel/workqueue.c:3276 [inline]
 process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 45:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x31c/0x660 mm/slub.c:5380
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 __hci_conn_add+0x3c4/0x1e00 net/bluetooth/hci_conn.c:963
 le_conn_complete_evt+0x706/0x1430 net/bluetooth/hci_event.c:5740
 hci_le_enh_conn_complete_evt+0x189/0x490 net/bluetooth/hci_event.c:5887
 hci_event_func net/bluetooth/hci_event.c:7781 [inline]
 hci_event_packet+0x7af/0x12c0 net/bluetooth/hci_event.c:7838
 hci_rx_work+0x3ee/0x1030 net/bluetooth/hci_core.c:4077
 process_one_work kernel/workqueue.c:3276 [inline]
 process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 4665:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x1c1/0x630 mm/slub.c:6483
 device_release+0x9e/0x1d0 drivers/base/core.c:-1
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x228/0x560 lib/kobject.c:737
 hci_conn_cleanup net/bluetooth/hci_conn.c:173 [inline]
 hci_conn_del+0xc36/0x1230 net/bluetooth/hci_conn.c:1240
 hci_disconn_complete_evt+0x64e/0x950 net/bluetooth/hci_event.c:3476
 hci_event_func net/bluetooth/hci_event.c:7784 [inline]
 hci_event_packet+0x805/0x12c0 net/bluetooth/hci_event.c:7838
 hci_rx_work+0x3ee/0x1030 net/bluetooth/hci_core.c:4077
 process_one_work kernel/workqueue.c:3276 [inline]
 process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff8880360c8000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 16 bytes inside of
 freed 8192-byte region [ffff8880360c8000, ffff8880360ca000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x360c8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff88801ac42280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000
head: 04fff00000000040 ffff88801ac42280 dead000000000100 dead000000000122
head: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000
head: 04fff00000000003 ffffea0000d83201 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 5012, tgid 5012 (dhcpcd), ts 50188110306, free_ts 48335496832
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3481
 new_slab mm/slub.c:3539 [inline]
 refill_objects+0x331/0x3c0 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x2e6/0x730 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kvmalloc_node_noprof+0x657/0x8a0 mm/slub.c:6752
 kvmalloc_array_node_noprof include/linux/slab.h:1216 [inline]
 __ptr_ring_init_queue_alloc_noprof include/linux/ptr_ring.h:481 [inline]
 ptr_ring_init_noprof include/linux/ptr_ring.h:499 [inline]
 skb_array_init_noprof include/linux/skb_array.h:182 [inline]
 pfifo_fast_init+0x112/0x6c0 net/sched/sch_generic.c:870
 qdisc_create_dflt+0x13b/0x510 net/sched/sch_generic.c:1013
 attach_one_default_qdisc net/sched/sch_generic.c:1172 [inline]
 netdev_for_each_tx_queue include/linux/netdevice.h:2684 [inline]
 attach_default_qdiscs net/sched/sch_generic.c:1190 [inline]
 dev_activate+0x378/0x1150 net/sched/sch_generic.c:1249