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BUG: KASAN: use-after-free in __lock_acquire+0x2cb4/0x3ff0 kernel/locking/lockdep.c:3295
Read of size 8 at addr ffff88809c9ee9e0 by task kworker/0:3/4714

CPU: 0 PID: 4714 Comm: kworker/0:3 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: events l2cap_chan_timeout
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1b9 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:3295
 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908
 __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:2884
 l2cap_sock_teardown_cb+0xa0/0x6d0 net/bluetooth/l2cap_sock.c:1348
 l2cap_chan_del+0xbc/0xa50 net/bluetooth/l2cap_core.c:603
 l2cap_chan_close+0x1b5/0x950 net/bluetooth/l2cap_core.c:761
 l2cap_chan_timeout+0x17e/0x2f0 net/bluetooth/l2cap_core.c:430
 process_one_work+0x864/0x1570 kernel/workqueue.c:2153
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Allocated by task 28444:
 kmem_cache_alloc_trace+0x12f/0x380 mm/slab.c:3625
 kmalloc include/linux/slab.h:515 [inline]
 kzalloc include/linux/slab.h:709 [inline]
 l2cap_chan_create+0x40/0x550 net/bluetooth/l2cap_core.c:444
 l2cap_sock_alloc.constprop.0+0x16c/0x210 net/bluetooth/l2cap_sock.c:1640
 l2cap_sock_create+0x123/0x1f0 net/bluetooth/l2cap_sock.c:1671
 bt_sock_create+0x154/0x2a0 net/bluetooth/af_bluetooth.c:130
 __sock_create+0x3d8/0x740 net/socket.c:1365
 sock_create net/socket.c:1416 [inline]
 __sys_socket+0xef/0x200 net/socket.c:1458
 __do_sys_socket net/socket.c:1467 [inline]
 __se_sys_socket net/socket.c:1465 [inline]
 __x64_sys_socket+0x6f/0xb0 net/socket.c:1465
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 28444:
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcc/0x210 mm/slab.c:3822
 l2cap_chan_destroy net/bluetooth/l2cap_core.c:484 [inline]
 kref_put include/linux/kref.h:70 [inline]
 l2cap_chan_put+0x1ee/0x270 net/bluetooth/l2cap_core.c:498
 l2cap_sock_release+0x1fb/0x290 net/bluetooth/l2cap_sock.c:1220
 __sock_release+0xcd/0x2a0 net/socket.c:599
 sock_close+0x15/0x20 net/socket.c:1214
 __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:2400
 do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:799
 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 ffff88809c9ee940
 which belongs to the cache kmalloc-2048 of size 2048
The buggy address is located 160 bytes inside of
 2048-byte region [ffff88809c9ee940, ffff88809c9ef140)
The buggy address belongs to the page:
page:ffffea0002727b80 count:1 mapcount:0 mapping:ffff88813bff0c40 index:0x0 compound_mapcount: 0
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 ffffea0002d6bb88 ffffea00028c1608 ffff88813bff0c40
raw: 0000000000000000 ffff88809c9ee0c0 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809c9ee880: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88809c9ee900: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff88809c9ee980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff88809c9eea00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88809c9eea80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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