[PATCH 4.9 36/44] USB: serial: io_ti: fix NULL-deref in interrupt callback

Greg Kroah-Hartman
2017-03-16T14:54:53Z

From: Johan Hovold <johan@kernel.org>

commit 0b1d250afb8eb9d65afb568bac9b9f9253a82b49 upstream.

Fix a NULL-pointer dereference in the interrupt callback should a
malicious device send data containing a bad port number by adding the
missing sanity check.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -1674,6 +1674,12 @@ static void edge_interrupt_callback(stru
function = TIUMP_GET_FUNC_FROM_CODE(data[0]);
dev_dbg(dev, "%s - port_number %d, function %d, info 0x%x\n", __func__,
port_number, function, data[1]);
+
+ if (port_number >= edge_serial->serial->num_ports) {
+ dev_err(dev, "bad port number %d\n", port_number);
+ goto exit;
+ }
+
port = edge_serial->serial->port[port_number];
edge_port = usb_get_serial_port_data(port);
if (!edge_port) {