ZhengHan Wang 3c4236f1b2 Bluetooth: Fix double free in hci_conn_cleanup
[ Upstream commit a85fb91e3d728bdfc80833167e8162cce8bc7004 ]

syzbot reports a slab use-after-free in hci_conn_hash_flush [1].
After releasing an object using hci_conn_del_sysfs in the
hci_conn_cleanup function, releasing the same object again
using the hci_dev_put and hci_conn_put functions causes a double free.
Here's a simplified flow:

hci_conn_del_sysfs:
  hci_dev_put
    put_device
      kobject_put
        kref_put
          kobject_release
            kobject_cleanup
              kfree_const
                kfree(name)

hci_dev_put:
  ...
    kfree(name)

hci_conn_put:
  put_device
    ...
      kfree(name)

This patch drop the hci_dev_put and hci_conn_put function
call in hci_conn_cleanup function, because the object is
freed in hci_conn_del_sysfs function.

This patch also fixes the refcounting in hci_conn_add_sysfs() and
hci_conn_del_sysfs() to take into account device_add() failures.

This fixes CVE-2023-28464.

Link: https://syzkaller.appspot.com/bug?id=1bb51491ca5df96a5f724899d1dbb87afda61419 [1]

Signed-off-by: ZhengHan Wang <wzhmmmmm@gmail.com>
Co-developed-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-28 16:50:14 +00:00
..
2023-06-09 10:28:59 +02:00
2022-04-20 09:19:40 +02:00
2023-10-10 21:46:37 +02:00
2023-07-27 08:37:40 +02:00
2023-10-25 11:53:19 +02:00
2023-06-21 15:44:10 +02:00
2023-01-18 11:41:09 +01:00
2023-09-23 10:59:43 +02:00
2023-05-17 11:35:59 +02:00
2023-07-27 08:37:23 +02:00
2023-10-25 11:53:21 +02:00
2021-06-18 09:59:00 +02:00
2023-06-21 15:44:10 +02:00
2023-06-21 15:44:10 +02:00