From: Jeremy Fitzhardinge <jeremy@goop.org>

strnlen prevents over-reading the input.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/util.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff -puN mm/util.c~add-kstrndup-fix mm/util.c
--- a/mm/util.c~add-kstrndup-fix
+++ a/mm/util.c
@@ -53,9 +53,7 @@ char *kstrndup(const char *s, size_t max
 	if (!s)
 		return NULL;
 
-	len = strlen(s);
-	if (len > max)
-		len = max;
+	len = strnlen(s, max);
 	buf = kmalloc_track_caller(len+1, gfp);
  	if (buf) {
 		memcpy(buf, s, len);
_