[PATCH 3.10 042/143] USB: serial: fix potential heap buffer overflow

From: Greg Kroah-Hartman
Date: Fri Oct 03 2014 - 18:56:13 EST


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

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

From: Johan Hovold <johan@xxxxxxxxxx>

commit 5654699fb38512bdbfc0f892ce54fce75bdc2bab upstream.

Make sure to verify the number of ports requested by subdriver to avoid
writing beyond the end of fixed-size array in interface data.

The current usb-serial implementation is limited to eight ports per
interface but failed to verify that the number of ports requested by a
subdriver (which could have been determined from device descriptors) did
not exceed this limit.

Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/usb/serial/usb-serial.c | 5 +++++
1 file changed, 5 insertions(+)

--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -876,6 +876,11 @@ static int usb_serial_probe(struct usb_i
num_ports = type->num_ports;
}

+ if (num_ports > MAX_NUM_PORTS) {
+ dev_warn(ddev, "too many ports requested: %d\n", num_ports);
+ num_ports = MAX_NUM_PORTS;
+ }
+
serial->num_ports = num_ports;
serial->num_bulk_in = num_bulk_in;
serial->num_bulk_out = num_bulk_out;


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