[PATCH 3.10 34/77] USB: sierra: fix use after free at suspend/resume

Greg Kroah-Hartman
2014-06-28T17:48:38Z

From: Johan Hovold <jhovold@gmail.com>

commit 8452727de70f6ad850cd6d0aaa18b5d9050aa63b upstream.

Fix use after free or NULL-pointer dereference during suspend and
resume.

The port data may never have been allocated (port probe failed)
or may already have been released by port_remove (e.g. driver is
unloaded) when suspend and resume are called.

Fixes: e6929a9020ac ("USB: support for autosuspend in sierra while
online")

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/usb/serial/sierra.c | 6 ++++++
1 file changed, 6 insertions(+)

--- a/drivers/usb/serial/sierra.c
+++ b/drivers/usb/serial/sierra.c
@@ -941,6 +941,7 @@ static int sierra_port_remove(struct usb
struct sierra_port_private *portdata;

portdata = usb_get_serial_port_data(port);
+ usb_set_serial_port_data(port, NULL);
kfree(portdata);

return 0;
@@ -957,6 +958,8 @@ static void stop_read_write_urbs(struct
for (i = 0; i < serial->num_ports; ++i) {
port = serial->port[i];
portdata = usb_get_serial_port_data(port);
+ if (!portdata)
+ continue;
sierra_stop_rx_urbs(port);
usb_kill_anchored_urbs(&portdata->active);
}
@@ -999,6 +1002,9 @@ static int sierra_resume(struct usb_seri
port = serial->port[i];
portdata = usb_get_serial_port_data(port);

+ if (!portdata)
+ continue;
+
while ((urb = usb_get_from_anchor(&portdata->delayed))) {
usb_anchor_urb(urb, &portdata->active);
intfdata->in_flight++;