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BUG: KASAN: use-after-free in __lock_acquire+0x40d0/0x5570 kernel/locking/lockdep.c:4296
Read of size 8 at addr ffff88809dd7c0a0 by task kworker/1:5/8288

CPU: 1 PID: 8288 Comm: kworker/1:5 Not tainted 5.9.0-rc3-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+0x198/0x1fd lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 __lock_acquire+0x40d0/0x5570 kernel/locking/lockdep.c:4296
 lock_acquire+0x1f3/0xae0 kernel/locking/lockdep.c:5006
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175
 spin_lock_bh include/linux/spinlock.h:359 [inline]
 lock_sock_nested+0x3b/0x110 net/core/sock.c:3048
 l2cap_sock_teardown_cb+0x88/0x400 net/bluetooth/l2cap_sock.c:1520
 l2cap_chan_del+0x114/0x1430 net/bluetooth/l2cap_core.c:619
 l2cap_chan_close+0x118/0xb10 net/bluetooth/l2cap_core.c:824
 l2cap_chan_timeout+0x173/0x450 net/bluetooth/l2cap_core.c:436
 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

The buggy address belongs to the page:
page:00000000f196561d refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0 pfn:0x9dd7c
flags: 0xfffe0000000000()
raw: 00fffe0000000000 ffffea000276b508 ffffea00026f9a88 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffff7f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809dd7bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88809dd7c000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88809dd7c080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff88809dd7c100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88809dd7c180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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