[PATCH 3.4 25/43] USB: sierra: fix use after free at suspend/resume

From: Greg Kroah-Hartman
Date: Sat Jun 28 2014 - 15:25:44 EST


3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Johan Hovold <jhovold@xxxxxxxxx>

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@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

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

--- a/drivers/usb/serial/sierra.c
+++ b/drivers/usb/serial/sierra.c
@@ -999,6 +999,7 @@ static void sierra_release(struct usb_se
portdata = usb_get_serial_port_data(port);
if (!portdata)
continue;
+ usb_set_serial_port_data(port, NULL);
kfree(portdata);
}
kfree(serial->private);
@@ -1015,6 +1016,8 @@ 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);
}
@@ -1057,6 +1060,9 @@ 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++;


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