USB: serial: io_ti: fix NULL-deref in interrupt callback
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>
[bwh: Backported to 3.2:
- Use &urb->dev->dev instead of local dev variable
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c
index 0fc2da9..a417756 100644
--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -1681,6 +1681,12 @@
function = TIUMP_GET_FUNC_FROM_CODE(data[0]);
dbg("%s - port_number %d, function %d, info 0x%x",
__func__, port_number, function, data[1]);
+
+ if (port_number >= edge_serial->serial->num_ports) {
+ dev_err(&urb->dev->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) {
