[klibc] [PATCH 1/2] strndup(): Fix out of bounds read access

[Romain Izard]

The use of strlen to get the length of the source string can lead to
undetermined memory access if the source string is not finished with a
zero. Use strnlen to prevent this.

Signed-off-by: Romain Izard <romain.izard.pro at gmail.com>
---
 usr/klibc/strndup.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/usr/klibc/strndup.c b/usr/klibc/strndup.c
index 65afd44..e4814be 100644
--- a/usr/klibc/strndup.c
+++ b/usr/klibc/strndup.c
@@ -7,9 +7,8 @@
 
 char *strndup(const char *s, size_t n)
 {
-	int l = n > strlen(s) ? strlen(s) + 1 : n + 1;
-	char *d = malloc(l);
-
+	size_t l = strnlen(s, n);
+	char *d = malloc(l + 1);
 	if (!d)
 		return NULL;
 
-- 
1.7.0.4