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BUG: KASAN: use-after-free in hci_chan_del+0x1b4/0x1f0 net/bluetooth/hci_conn.c:1683
Read of size 8 at addr ffff88809d630d98 by task syz-executor.5/14566

CPU: 0 PID: 14566 Comm: syz-executor.5 Not tainted 4.19.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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
 hci_chan_del+0x1b4/0x1f0 net/bluetooth/hci_conn.c:1683
 l2cap_conn_del+0x45e/0x6e0 net/bluetooth/l2cap_core.c:1739
 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7441 [inline]
 l2cap_disconn_cfm+0x98/0xd0 net/bluetooth/l2cap_core.c:7434
 hci_disconn_cfm include/net/bluetooth/hci_core.h:1261 [inline]
 hci_conn_hash_flush+0x127/0x260 net/bluetooth/hci_conn.c:1512
 hci_dev_do_close+0x659/0xf10 net/bluetooth/hci_core.c:1668
 hci_unregister_dev+0x18b/0x910 net/bluetooth/hci_core.c:3273
 vhci_release+0x70/0xe0 drivers/bluetooth/hci_vhci.c:354
 __fput+0x2ce/0x890 fs/file_table.c:278
 task_work_run+0x148/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0xbf3/0x2be0 kernel/exit.c:870
 do_group_exit+0x125/0x310 kernel/exit.c:967
 get_signal+0x3f2/0x1f70 kernel/signal.c:2589
 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
RIP: 0033:0x465f69
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7f6c929218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000056bf68 RCX: 0000000000465f69
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056bf68
RBP: 000000000056bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf6c
R13: 00007ffe320fd62f R14: 00007f7f6c929300 R15: 0000000000022000

Allocated by task 8120:
 kmem_cache_alloc_trace+0x12f/0x380 mm/slab.c:3625
 kmalloc include/linux/slab.h:515 [inline]
 sock_alloc_inode+0x5f/0x250 net/socket.c:247
 alloc_inode+0x5d/0x180 fs/inode.c:211
 new_inode_pseudo+0x14/0xe0 fs/inode.c:911
 sock_alloc+0x3c/0x260 net/socket.c:547
 __sock_create+0xba/0x740 net/socket.c:1240
 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 9:
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcc/0x210 mm/slab.c:3822
 __rcu_reclaim kernel/rcu/rcu.h:231 [inline]
 rcu_do_batch kernel/rcu/tree.c:2584 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2897 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2864 [inline]
 rcu_process_callbacks+0xa0d/0x18b0 kernel/rcu/tree.c:2881
 __do_softirq+0x265/0x980 kernel/softirq.c:292

The buggy address belongs to the object at ffff88809d630d80
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 24 bytes inside of
 128-byte region [ffff88809d630d80, ffff88809d630e00)
The buggy address belongs to the page:
page:ffffea0002758c00 count:1 mapcount:0 mapping:ffff88813bff0640 index:0xffff88809d630e40
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffffea000268edc8 ffffea0002508988 ffff88813bff0640
raw: ffff88809d630e40 ffff88809d630000 0000000100000013 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809d630c80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 ffff88809d630d00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff88809d630d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88809d630e00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 ffff88809d630e80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
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