[PATCH] USB: Buffer overflow patch for Yealink driver

Just a small patch that fixes a small parameter validation bug.

  drivers/usb/input/map_to_7segment.h:
    This patch fixes the broken parameter validation in the char to seg7
    conversion. This could cause out-of-bounds memory references.

  MAINTAINERS:
    Yealink maintainer info now in sorted order.

  Documentation/input/yealink.txt:
    Added a Q&A section that answers some common questions.

Signed-off-by: Henk <Henk.Vergonet@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

006491df1a13f85ad245d1039dfdf20e49c394fd
diff --git a/drivers/usb/input/map_to_7segment.h b/drivers/usb/input/map_to_7segment.h
index 52ff27f..a424094 100644
--- a/drivers/usb/input/map_to_7segment.h
+++ b/drivers/usb/input/map_to_7segment.h
@@ -79,7 +79,7 @@
 
 static inline int map_to_seg7(struct seg7_conversion_map *map, int c)
 {
-	return c & 0x7f ? map->table[c] : -EINVAL;
+	return c >= 0 && c < sizeof(map->table) ? map->table[c] : -EINVAL;
 }
 
 #define SEG7_CONVERSION_MAP(_name, _map)	\