atm: fix atm_dev refcnt leaks in atmtcp_remove_persistent

atmtcp_remove_persistent() invokes atm_dev_lookup(), which returns a
reference of atm_dev with increased refcount or NULL if fails.

The refcount leaks issues occur in two error handling paths. If
dev_data->persist is zero or PRIV(dev)->vcc isn't NULL, the function
returns 0 without decreasing the refcount kept by a local variable,
resulting in refcount leaks.

Fix the issue by adding atm_dev_put() before returning 0 both when
dev_data->persist is zero or PRIV(dev)->vcc isn't NULL.

Signed-off-by: Xin Xiong <xiongx18@fudan.edu.cn>
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Xin Xiong 2020-07-29 21:06:59 +08:00 committed by David S. Miller
parent 555a893303
commit 51875dad43

View File

@ -433,9 +433,15 @@ static int atmtcp_remove_persistent(int itf)
return -EMEDIUMTYPE;
}
dev_data = PRIV(dev);
if (!dev_data->persist) return 0;
if (!dev_data->persist) {
atm_dev_put(dev);
return 0;
}
dev_data->persist = 0;
if (PRIV(dev)->vcc) return 0;
if (PRIV(dev)->vcc) {
atm_dev_put(dev);
return 0;
}
kfree(dev_data);
atm_dev_put(dev);
atm_dev_deregister(dev);