Added null check for character class. Previously, an inverted character 
class could result in a nul byte being matched and lead to the function 
reading past the end of the inputted str.

Signed-off-by: Alok Swaminathan <swaminathanalok@gmail.com>
---
 lib/glob.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/glob.c b/lib/glob.c
index 15b73f490720..aa57900d2062 100644
--- a/lib/glob.c
+++ b/lib/glob.c
@@ -68,6 +68,8 @@ bool __pure glob_match(char const *pat, char const *str)
 			back_str = --str;	/* Allow zero-length match */
 			break;
 		case '[': {	/* Character class */
+			if (c == '\0')	/* No possible match */
+				return false;
 			bool match = false, inverted = (*pat == '!');
 			char const *class = pat + inverted;
 			unsigned char a = *class++;
-- 
2.46.0