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BUG: KASAN: use-after-free in __lock_acquire+0x3ad2/0x5050 kernel/locking/lockdep.c:4770
Read of size 8 at addr ffff88811d3970a0 by task kworker/0:2/1310

CPU: 0 PID: 1310 Comm: kworker/0:2 Not tainted 5.12.0-rc2-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:79 [inline]
 dump_stack+0x10c/0x14b lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x5b/0x2c6 mm/kasan/report.c:232
 __kasan_report mm/kasan/report.c:399 [inline]
 kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416
 __lock_acquire+0x3ad2/0x5050 kernel/locking/lockdep.c:4770
 lock_acquire kernel/locking/lockdep.c:5510 [inline]
 lock_acquire+0x212/0x850 kernel/locking/lockdep.c:5475
 __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+0x39/0xf0 net/core/sock.c:3063
 l2cap_sock_teardown_cb+0x83/0x3a0 net/bluetooth/l2cap_sock.c:1520
 l2cap_chan_del+0x96/0x1010 net/bluetooth/l2cap_core.c:618
 l2cap_chan_close+0xe2/0x9d0 net/bluetooth/l2cap_core.c:823
 l2cap_chan_timeout+0x122/0x3a0 net/bluetooth/l2cap_core.c:436
 process_one_work+0x84c/0x13b0 kernel/workqueue.c:2275
 worker_thread+0x598/0xf80 kernel/workqueue.c:2421
 kthread+0x36f/0x450 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Allocated by task 3538:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:427 [inline]
 ____kasan_kmalloc mm/kasan/common.c:506 [inline]
 __kasan_kmalloc+0x78/0x90 mm/kasan/common.c:515
 kasan_kmalloc include/linux/kasan.h:233 [inline]
 __do_kmalloc mm/slab.c:3695 [inline]
 __kmalloc+0x22f/0x440 mm/slab.c:3704
 kmalloc include/linux/slab.h:559 [inline]
 sk_prot_alloc+0x10c/0x200 net/core/sock.c:1703
 sk_alloc+0x27/0x8d0 net/core/sock.c:1756
 __netlink_create+0x58/0x2a0 net/netlink/af_netlink.c:638
 netlink_create+0x2f9/0x530 net/netlink/af_netlink.c:701
 __sock_create+0x257/0x540 net/socket.c:1408
 sock_create net/socket.c:1459 [inline]
 __sys_socket+0xd6/0x1a0 net/socket.c:1501
 __do_sys_socket net/socket.c:1510 [inline]
 __se_sys_socket net/socket.c:1508 [inline]
 __x64_sys_socket+0x6a/0xb0 net/socket.c:1508
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 18:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357
 ____kasan_slab_free mm/kasan/common.c:360 [inline]
 ____kasan_slab_free mm/kasan/common.c:325 [inline]
 __kasan_slab_free+0xac/0xe0 mm/kasan/common.c:367
 kasan_slab_free include/linux/kasan.h:199 [inline]
 __cache_free mm/slab.c:3440 [inline]
 kfree+0x10f/0x2d0 mm/slab.c:3796
 sk_prot_free net/core/sock.c:1739 [inline]
 __sk_destruct+0x4da/0x6c0 net/core/sock.c:1824
 rcu_do_batch kernel/rcu/tree.c:2559 [inline]
 rcu_core+0x722/0x14f0 kernel/rcu/tree.c:2794
 __do_softirq+0x206/0xa44 kernel/softirq.c:345

Last potentially related work creation:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_record_aux_stack+0x87/0xb0 mm/kasan/generic.c:345
 __call_rcu kernel/rcu/tree.c:3039 [inline]
 call_rcu+0x118/0x7c0 kernel/rcu/tree.c:3114
 netlink_release+0xafa/0x17d0 net/netlink/af_netlink.c:810
 __sock_release+0xbb/0x270 net/socket.c:599
 sock_close+0xf/0x20 net/socket.c:1258
 __fput+0x209/0x870 fs/file_table.c:280
 task_work_run+0xc0/0x160 kernel/task_work.c:140
 exit_task_work include/linux/task_work.h:30 [inline]
 do_exit+0xac8/0x25b0 kernel/exit.c:825
 do_group_exit+0xe7/0x290 kernel/exit.c:922
 __do_sys_exit_group kernel/exit.c:933 [inline]
 __se_sys_exit_group kernel/exit.c:931 [inline]
 __x64_sys_exit_group+0x35/0x40 kernel/exit.c:931
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff88811d397000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 160 bytes inside of
 2048-byte region [ffff88811d397000, ffff88811d397800)
The buggy address belongs to the page:
page:00000000048d935b refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11d397
flags: 0x17ffe0000000200(slab)
raw: 017ffe0000000200 ffffea000474e588 ffffea0004712508 ffff888100040800
raw: 0000000000000000 ffff88811d397000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88811d396f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88811d397000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88811d397080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff88811d397100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88811d397180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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