linux/net/bluetooth
Thadeu Lima de Souza Cascardo fe201316ac Bluetooth: cmtp: fix file refcount when cmtp_attach_device fails
commit 8da3a0b87f4f1c3a3bbc4bfb78cf68476e97d183 upstream.

When cmtp_attach_device fails, cmtp_add_connection returns the error value
which leads to the caller to doing fput through sockfd_put. But
cmtp_session kthread, which is stopped in this path will also call fput,
leading to a potential refcount underflow or a use-after-free.

Add a refcount before we signal the kthread to stop. The kthread will try
to grab the cmtp_session_sem mutex before doing the fput, which is held
when get_file is called, so there should be no races there.

Reported-by: Ryota Shiga
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-03 08:59:06 +02:00
..
2021-05-11 14:04:16 +02:00
2019-07-26 14:58:12 +10:00
2017-09-01 22:49:47 +02:00
2019-04-19 14:07:40 -07:00
2018-09-26 12:39:32 +03:00