memdbg: Accept short strings in md_strndup()

Don't fail if string to duplicate is shorter than the size parameter
and handle memory allocation failure.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>

1 files changed, 9 insertions, 4 deletions

diff --git a/accel-pppd/memdebug.c b/accel-pppd/memdebug.c
index 8c3c494f..5629146a 100644
--- a/accel-pppd/memdebug.c
+++ b/accel-pppd/memdebug.c
@@ -153,10 +153,15 @@ char __export *md_strdup(const char *ptr, const char *fname, int line)
 
 char __export *md_strndup(const char *ptr, size_t n, const char *fname, int line)
 {
-	struct mem_t *mem = _md_malloc(n + 1, fname, line);
-	memcpy(mem->data, ptr, n);
-	mem->data[n] = 0;
-	return mem->data;
+	size_t len = strnlen(ptr, n);
+	char *str = md_malloc(len + 1, fname, line);
+
+	if (str) {
+		memcpy(str, ptr, len);
+		str[len] = '\0';
+	}
+
+	return str;
 }
 
 static void siginfo(int num)