Staging: speakup: fix an out-of-bounds error.

The cur_item variable from keyhelp.c is an index into a table of
messages.  The following condition should always hold:
MSG_FUNCNAMES_START + cur_item <= MSG_FUNCNAMES_END.
The check in keyhelp.c was wrong.  It allowed cur_item to be
incremented to an out-of-bounds value.

Signed-off-by: Christopher Brannon <chris@the-brannons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/staging/speakup/keyhelp.c b/drivers/staging/speakup/keyhelp.c
index 236f06d35ca6..23cf7f44f450 100644
--- a/drivers/staging/speakup/keyhelp.c
+++ b/drivers/staging/speakup/keyhelp.c
@@ -161,7 +161,9 @@ int handle_help(struct vc_data *vc, u_char type, u_char ch, u_short key)
                 }
         cur_item = letter_offsets[ch-'a'];
         } else if (type == KT_CUR) {
-                if (ch == 0 && (cur_item + 1) <= MSG_FUNCNAMES_END)
+                if (ch == 0
+                    && (MSG_FUNCNAMES_START + cur_item + 1) <=
+                    MSG_FUNCNAMES_END)
                         cur_item++;
                 else if (ch == 3 && cur_item > 0)
                         cur_item--;