==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x2cb4/0x3ff0 kernel/locking/lockdep.c:3294
Read of size 8 at addr ffff88809e871260 by task kworker/0:2/6660

CPU: 0 PID: 6660 Comm: kworker/0:2 Not tainted 4.19.138-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events l2cap_chan_timeout
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2fe lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1c7 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433
 __lock_acquire+0x2cb4/0x3ff0 kernel/locking/lockdep.c:3294
 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3907
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:168
 spin_lock_bh include/linux/spinlock.h:334 [inline]
 lock_sock_nested+0x3b/0x110 net/core/sock.c:2843
 l2cap_sock_teardown_cb+0x88/0x460 net/bluetooth/l2cap_sock.c:1328
 l2cap_chan_close+0x2b5/0x820 net/bluetooth/l2cap_core.c:758
 l2cap_chan_timeout+0x16d/0x210 net/bluetooth/l2cap_core.c:427
 process_one_work+0x864/0x1570 kernel/workqueue.c:2155
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2298
 kthread+0x30b/0x410 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Allocated by task 7708:
 __do_kmalloc mm/slab.c:3727 [inline]
 __kmalloc+0x15a/0x3c0 mm/slab.c:3736
 kmalloc include/linux/slab.h:520 [inline]
 sk_prot_alloc+0x1e2/0x2d0 net/core/sock.c:1466
 sk_alloc+0x36/0xec0 net/core/sock.c:1520
 l2cap_sock_alloc.constprop.0+0x31/0x210 net/bluetooth/l2cap_sock.c:1590
 l2cap_sock_create+0x110/0x1b0 net/bluetooth/l2cap_sock.c:1636
 bt_sock_create+0x154/0x2a0 net/bluetooth/af_bluetooth.c:130
 __sock_create+0x3d8/0x740 net/socket.c:1276
 sock_create net/socket.c:1316 [inline]
 __sys_socket+0xef/0x200 net/socket.c:1346
 __do_sys_socket net/socket.c:1355 [inline]
 __se_sys_socket net/socket.c:1353 [inline]
 __x64_sys_socket+0x6f/0xb0 net/socket.c:1353
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 7707:
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcc/0x210 mm/slab.c:3822
 sk_prot_free net/core/sock.c:1503 [inline]
 __sk_destruct+0x5ff/0x810 net/core/sock.c:1584
 sk_destruct net/core/sock.c:1599 [inline]
 __sk_free+0x165/0x3b0 net/core/sock.c:1610
 sk_free+0x3b/0x50 net/core/sock.c:1621
 sock_put include/net/sock.h:1707 [inline]
 l2cap_sock_kill.part.0+0x6b/0x80 net/bluetooth/l2cap_sock.c:1055
 l2cap_sock_kill net/bluetooth/l2cap_sock.c:1206 [inline]
 l2cap_sock_release+0x158/0x190 net/bluetooth/l2cap_sock.c:1204
 __sock_release+0xcd/0x2a0 net/socket.c:579
 sock_close+0x15/0x20 net/socket.c:1140
 __fput+0x2ce/0x890 fs/file_table.c:278
 task_work_run+0x148/0x1c0 kernel/task_work.c:113
 get_signal+0x1b64/0x1f70 kernel/signal.c:2399
 do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:821
 exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88809e8711c0
 which belongs to the cache kmalloc-2048 of size 2048
The buggy address is located 160 bytes inside of
 2048-byte region [ffff88809e8711c0, ffff88809e8719c0)
The buggy address belongs to the page:
page:ffffea00027a1c00 count:1 mapcount:0 mapping:ffff88812c39cc40 index:0x0 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffffea000210ce88 ffffea00021c5f08 ffff88812c39cc40
raw: 0000000000000000 ffff88809e8700c0 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809e871100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88809e871180: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff88809e871200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff88809e871280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88809e871300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================