4 files changed, 8 insertions, 0 deletions

diff --git a/lib/libc/stdio/snprintf.c b/lib/libc/stdio/snprintf.c
index fe21129bc13f..3463c05f9876 100644
--- a/lib/libc/stdio/snprintf.c
+++ b/lib/libc/stdio/snprintf.c
@@ -87,5 +87,7 @@ snprintf(str, n, fmt, va_alist)
 	if (on > 0)
 		*f._p = '\0';
 	va_end(ap);
+	if (str == NULL)
+		free(f._bf._base);
 	return (ret);
 }
diff --git a/lib/libc/stdio/sprintf.c b/lib/libc/stdio/sprintf.c
index a8100961fa4d..04910e02e6cd 100644
--- a/lib/libc/stdio/sprintf.c
+++ b/lib/libc/stdio/sprintf.c
@@ -77,5 +77,7 @@ sprintf(str, fmt, va_alist)
 	ret = __vfprintf(&f, fmt, ap);
 	va_end(ap);
 	*f._p = 0;
+	if (str == NULL)
+		free(f._bf._base);
 	return (ret);
 }
diff --git a/lib/libc/stdio/vsnprintf.c b/lib/libc/stdio/vsnprintf.c
index b301b08f9fe5..3b762599933f 100644
--- a/lib/libc/stdio/vsnprintf.c
+++ b/lib/libc/stdio/vsnprintf.c
@@ -69,5 +69,7 @@ vsnprintf(str, n, fmt, ap)
 	ret = __vfprintf(&f, fmt, ap);
 	if (on > 0)
 		*f._p = '\0';
+	if (str == NULL)
+		free(f._bf._base);
 	return (ret);
 }
diff --git a/lib/libc/stdio/vsprintf.c b/lib/libc/stdio/vsprintf.c
index dbfd339e2d3e..9bcd0753e982 100644
--- a/lib/libc/stdio/vsprintf.c
+++ b/lib/libc/stdio/vsprintf.c
@@ -61,5 +61,7 @@ vsprintf(str, fmt, ap)
 	f._bf._size = f._w = INT_MAX;
 	ret = __vfprintf(&f, fmt, ap);
 	*f._p = 0;
+	if (str == NULL)
+		free(f._bf._base);
 	return (ret);
 }