staging: line6: add bounds check in snd_toneport_source_put()

"source" comes from the user in snd_ctl_elem_write() so it needs to be
checked.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 7 insertions, 3 deletions

diff --git a/drivers/staging/line6/toneport.c b/drivers/staging/line6/toneport.c
index 2f44d56700af..776d3632dc7d 100644
--- a/drivers/staging/line6/toneport.c
+++ b/drivers/staging/line6/toneport.c
@@ -244,13 +244,17 @@ static int snd_toneport_source_put(struct snd_kcontrol *kcontrol,
         struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
         struct usb_line6_toneport *toneport =
             (struct usb_line6_toneport *)line6pcm->line6;
+        unsigned int source;
 
-        if (ucontrol->value.enumerated.item[0] == toneport->source)
+        source = ucontrol->value.enumerated.item[0];
+        if (source >= ARRAY_SIZE(toneport_source_info))
+                return -EINVAL;
+        if (source == toneport->source)
                 return 0;
 
-        toneport->source = ucontrol->value.enumerated.item[0];
+        toneport->source = source;
         toneport_send_cmd(toneport->line6.usbdev,
-                          toneport_source_info[toneport->source].code, 0x0000);
+                          toneport_source_info[source].code, 0x0000);
         return 1;
 }