Fix a stack smash

It occurs when memory compares are made that are larger
than the on stack temporary buffers (either malloced or supplied).

Rework the test test so it doesn't use a macro with a branch.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3155)

2 files changed, 207 insertions, 162 deletions

diff --git a/test/test_test.c b/test/test_test.c
index 879a051a59..9f365d4936 100644
--- a/test/test_test.c
+++ b/test/test_test.c
@@ -21,28 +21,34 @@
 #include "e_os.h"
 #include "testutil.h"
 
-#define C(l, b, t)                                      \
-    if ((t) != b) {                                     \
-        fprintf(stderr, "FATAL : %s != %d\n", #t, b);   \
-        goto l;                                         \
+#define TEST(expected, test) test_case((expected), #test, (test))
+
+static int test_case(int expected, const char *test, int result)
+{
+    if (result != expected) {
+        fprintf(stderr, "FATAL: %s != %d\n", test, expected);
+        return 0;
     }
+    return 1;
+}
 
 static int test_int(void)
 {
-    C(err, 1, TEST_int_eq(1, 1));
-    C(err, 0, TEST_int_eq(1, -1));
-    C(err, 1, TEST_int_ne(1, 2));
-    C(err, 0, TEST_int_ne(3, 3));
-    C(err, 1, TEST_int_lt(4, 9));
-    C(err, 0, TEST_int_lt(9, 4));
-    C(err, 1, TEST_int_le(4, 9));
-    C(err, 1, TEST_int_le(5, 5));
-    C(err, 0, TEST_int_le(9, 4));
-    C(err, 1, TEST_int_gt(8, 5));
-    C(err, 0, TEST_int_gt(5, 8));
-    C(err, 1, TEST_int_ge(8, 5));
-    C(err, 1, TEST_int_ge(6, 6));
-    C(err, 0, TEST_int_ge(5, 8));
+    if (!TEST(1, TEST_int_eq(1, 1))
+        | !TEST(0, TEST_int_eq(1, -1))
+        | !TEST(1, TEST_int_ne(1, 2))
+        | !TEST(0, TEST_int_ne(3, 3))
+        | !TEST(1, TEST_int_lt(4, 9))
+        | !TEST(0, TEST_int_lt(9, 4))
+        | !TEST(1, TEST_int_le(4, 9))
+        | !TEST(1, TEST_int_le(5, 5))
+        | !TEST(0, TEST_int_le(9, 4))
+        | !TEST(1, TEST_int_gt(8, 5))
+        | !TEST(0, TEST_int_gt(5, 8))
+        | !TEST(1, TEST_int_ge(8, 5))
+        | !TEST(1, TEST_int_ge(6, 6))
+        | !TEST(0, TEST_int_ge(5, 8)))
+        goto err;
     return 1;
 
 err:
@@ -51,20 +57,21 @@ err:
 
 static int test_uint(void)
 {
-    C(err, 1, TEST_uint_eq(3u, 3u));
-    C(err, 0, TEST_uint_eq(3u, 5u));
-    C(err, 1, TEST_uint_ne(4u, 2u));
-    C(err, 0, TEST_uint_ne(6u, 6u));
-    C(err, 1, TEST_uint_lt(5u, 9u));
-    C(err, 0, TEST_uint_lt(9u, 5u));
-    C(err, 1, TEST_uint_le(5u, 9u));
-    C(err, 1, TEST_uint_le(7u, 7u));
-    C(err, 0, TEST_uint_le(9u, 5u));
-    C(err, 1, TEST_uint_gt(11u, 1u));
-    C(err, 0, TEST_uint_gt(1u, 11u));
-    C(err, 1, TEST_uint_ge(11u, 1u));
-    C(err, 1, TEST_uint_ge(6u, 6u));
-    C(err, 0, TEST_uint_ge(1u, 11u));
+    if (!TEST(1, TEST_uint_eq(3u, 3u))
+        | !TEST(0, TEST_uint_eq(3u, 5u))
+        | !TEST(1, TEST_uint_ne(4u, 2u))
+        | !TEST(0, TEST_uint_ne(6u, 6u))
+        | !TEST(1, TEST_uint_lt(5u, 9u))
+        | !TEST(0, TEST_uint_lt(9u, 5u))
+        | !TEST(1, TEST_uint_le(5u, 9u))
+        | !TEST(1, TEST_uint_le(7u, 7u))
+        | !TEST(0, TEST_uint_le(9u, 5u))
+        | !TEST(1, TEST_uint_gt(11u, 1u))
+        | !TEST(0, TEST_uint_gt(1u, 11u))
+        | !TEST(1, TEST_uint_ge(11u, 1u))
+        | !TEST(1, TEST_uint_ge(6u, 6u))
+        | !TEST(0, TEST_uint_ge(1u, 11u)))
+        goto err;
     return 1;
 
 err:
@@ -73,20 +80,21 @@ err:
 
 static int test_char(void)
 {
-    C(err, 1, TEST_char_eq('a', 'a'));
-    C(err, 0, TEST_char_eq('a', 'A'));
-    C(err, 1, TEST_char_ne('a', 'c'));
-    C(err, 0, TEST_char_ne('e', 'e'));
-    C(err, 1, TEST_char_lt('i', 'x'));
-    C(err, 0, TEST_char_lt('x', 'i'));
-    C(err, 1, TEST_char_le('i', 'x'));
-    C(err, 1, TEST_char_le('n', 'n'));
-    C(err, 0, TEST_char_le('x', 'i'));
-    C(err, 1, TEST_char_gt('w', 'n'));
-    C(err, 0, TEST_char_gt('n', 'w'));
-    C(err, 1, TEST_char_ge('w', 'n'));
-    C(err, 1, TEST_char_ge('p', 'p'));
-    C(err, 0, TEST_char_ge('n', 'w'));
+    if (!TEST(1, TEST_char_eq('a', 'a'))
+        | !TEST(0, TEST_char_eq('a', 'A'))
+        | !TEST(1, TEST_char_ne('a', 'c'))
+        | !TEST(0, TEST_char_ne('e', 'e'))
+        | !TEST(1, TEST_char_lt('i', 'x'))
+        | !TEST(0, TEST_char_lt('x', 'i'))
+        | !TEST(1, TEST_char_le('i', 'x'))
+        | !TEST(1, TEST_char_le('n', 'n'))
+        | !TEST(0, TEST_char_le('x', 'i'))
+        | !TEST(1, TEST_char_gt('w', 'n'))
+        | !TEST(0, TEST_char_gt('n', 'w'))
+        | !TEST(1, TEST_char_ge('w', 'n'))
+        | !TEST(1, TEST_char_ge('p', 'p'))
+        | !TEST(0, TEST_char_ge('n', 'w')))
+        goto err;
     return 1;
 
 err:
@@ -95,20 +103,21 @@ err:
 
 static int test_uchar(void)
 {
-    C(err, 1, TEST_uchar_eq(49, 49));
-    C(err, 0, TEST_uchar_eq(49, 60));
-    C(err, 1, TEST_uchar_ne(50, 2));
-    C(err, 0, TEST_uchar_ne(66, 66));
-    C(err, 1, TEST_uchar_lt(60, 80));
-    C(err, 0, TEST_uchar_lt(80, 60));
-    C(err, 1, TEST_uchar_le(60, 80));
-    C(err, 1, TEST_uchar_le(78, 78));
-    C(err, 0, TEST_uchar_le(80, 60));
-    C(err, 1, TEST_uchar_gt(88, 37));
-    C(err, 0, TEST_uchar_gt(37, 88));
-    C(err, 1, TEST_uchar_ge(88, 37));
-    C(err, 1, TEST_uchar_ge(66, 66));
-    C(err, 0, TEST_uchar_ge(37, 88));
+    if (!TEST(1, TEST_uchar_eq(49, 49))
+        | !TEST(0, TEST_uchar_eq(49, 60))
+        | !TEST(1, TEST_uchar_ne(50, 2))
+        | !TEST(0, TEST_uchar_ne(66, 66))
+        | !TEST(1, TEST_uchar_lt(60, 80))
+        | !TEST(0, TEST_uchar_lt(80, 60))
+        | !TEST(1, TEST_uchar_le(60, 80))
+        | !TEST(1, TEST_uchar_le(78, 78))
+        | !TEST(0, TEST_uchar_le(80, 60))
+        | !TEST(1, TEST_uchar_gt(88, 37))
+        | !TEST(0, TEST_uchar_gt(37, 88))
+        | !TEST(1, TEST_uchar_ge(88, 37))
+        | !TEST(1, TEST_uchar_ge(66, 66))
+        | !TEST(0, TEST_uchar_ge(37, 88)))
+        goto err;
     return 1;
 
 err:
@@ -117,20 +126,21 @@ err:
 
 static int test_long(void)
 {
-    C(err, 1, TEST_long_eq(123l, 123l));
-    C(err, 0, TEST_long_eq(123l, -123l));
-    C(err, 1, TEST_long_ne(123l, 500l));
-    C(err, 0, TEST_long_ne(1000l, 1000l));
-    C(err, 1, TEST_long_lt(-8923l, 102934563l));
-    C(err, 0, TEST_long_lt(102934563l, -8923l));
-    C(err, 1, TEST_long_le(-8923l, 102934563l));
-    C(err, 1, TEST_long_le(12345l, 12345l));
-    C(err, 0, TEST_long_le(102934563l, -8923l));
-    C(err, 1, TEST_long_gt(84325677l, 12345l));
-    C(err, 0, TEST_long_gt(12345l, 84325677l));
-    C(err, 1, TEST_long_ge(84325677l, 12345l));
-    C(err, 1, TEST_long_ge(465869l, 465869l));
-    C(err, 0, TEST_long_ge(12345l, 84325677l));
+    if (!TEST(1, TEST_long_eq(123l, 123l))
+        | !TEST(0, TEST_long_eq(123l, -123l))
+        | !TEST(1, TEST_long_ne(123l, 500l))
+        | !TEST(0, TEST_long_ne(1000l, 1000l))
+        | !TEST(1, TEST_long_lt(-8923l, 102934563l))
+        | !TEST(0, TEST_long_lt(102934563l, -8923l))
+        | !TEST(1, TEST_long_le(-8923l, 102934563l))
+        | !TEST(1, TEST_long_le(12345l, 12345l))
+        | !TEST(0, TEST_long_le(102934563l, -8923l))
+        | !TEST(1, TEST_long_gt(84325677l, 12345l))
+        | !TEST(0, TEST_long_gt(12345l, 84325677l))
+        | !TEST(1, TEST_long_ge(84325677l, 12345l))
+        | !TEST(1, TEST_long_ge(465869l, 465869l))
+        | !TEST(0, TEST_long_ge(12345l, 84325677l)))
+        goto err;
     return 1;
 
 err:
@@ -139,20 +149,21 @@ err:
 
 static int test_ulong(void)
 {
-    C(err, 1, TEST_ulong_eq(919ul, 919ul));
-    C(err, 0, TEST_ulong_eq(919ul, 10234ul));
-    C(err, 1, TEST_ulong_ne(8190ul, 66ul));
-    C(err, 0, TEST_ulong_ne(10555ul, 10555ul));
-    C(err, 1, TEST_ulong_lt(10234ul, 1000000ul));
-    C(err, 0, TEST_ulong_lt(1000000ul, 10234ul));
-    C(err, 1, TEST_ulong_le(10234ul, 1000000ul));
-    C(err, 1, TEST_ulong_le(100000ul, 100000ul));
-    C(err, 0, TEST_ulong_le(1000000ul, 10234ul));
-    C(err, 1, TEST_ulong_gt(100000000ul, 22ul));
-    C(err, 0, TEST_ulong_gt(22ul, 100000000ul));
-    C(err, 1, TEST_ulong_ge(100000000ul, 22ul));
-    C(err, 1, TEST_ulong_ge(10555ul, 10555ul));
-    C(err, 0, TEST_ulong_ge(22ul, 100000000ul));
+    if (!TEST(1, TEST_ulong_eq(919ul, 919ul))
+        | !TEST(0, TEST_ulong_eq(919ul, 10234ul))
+        | !TEST(1, TEST_ulong_ne(8190ul, 66ul))
+        | !TEST(0, TEST_ulong_ne(10555ul, 10555ul))
+        | !TEST(1, TEST_ulong_lt(10234ul, 1000000ul))
+        | !TEST(0, TEST_ulong_lt(1000000ul, 10234ul))
+        | !TEST(1, TEST_ulong_le(10234ul, 1000000ul))
+        | !TEST(1, TEST_ulong_le(100000ul, 100000ul))
+        | !TEST(0, TEST_ulong_le(1000000ul, 10234ul))
+        | !TEST(1, TEST_ulong_gt(100000000ul, 22ul))
+        | !TEST(0, TEST_ulong_gt(22ul, 100000000ul))
+        | !TEST(1, TEST_ulong_ge(100000000ul, 22ul))
+        | !TEST(1, TEST_ulong_ge(10555ul, 10555ul))
+        | !TEST(0, TEST_ulong_ge(22ul, 100000000ul)))
+        goto err;
     return 1;
 
 err:
@@ -161,20 +172,21 @@ err:
 
 static int test_size_t(void)
 {
-    C(err, 1, TEST_int_eq((size_t)10, (size_t)10));
-    C(err, 0, TEST_int_eq((size_t)10, (size_t)12));
-    C(err, 1, TEST_int_ne((size_t)10, (size_t)12));
-    C(err, 0, TEST_int_ne((size_t)24, (size_t)24));
-    C(err, 1, TEST_int_lt((size_t)30, (size_t)88));
-    C(err, 0, TEST_int_lt((size_t)88, (size_t)30));
-    C(err, 1, TEST_int_le((size_t)30, (size_t)88));
-    C(err, 1, TEST_int_le((size_t)33, (size_t)33));
-    C(err, 0, TEST_int_le((size_t)88, (size_t)30));
-    C(err, 1, TEST_int_gt((size_t)52, (size_t)33));
-    C(err, 0, TEST_int_gt((size_t)33, (size_t)52));
-    C(err, 1, TEST_int_ge((size_t)52, (size_t)33));
-    C(err, 1, TEST_int_ge((size_t)38, (size_t)38));
-    C(err, 0, TEST_int_ge((size_t)33, (size_t)52));
+    if (!TEST(1, TEST_int_eq((size_t)10, (size_t)10))
+        | !TEST(0, TEST_int_eq((size_t)10, (size_t)12))
+        | !TEST(1, TEST_int_ne((size_t)10, (size_t)12))
+        | !TEST(0, TEST_int_ne((size_t)24, (size_t)24))
+        | !TEST(1, TEST_int_lt((size_t)30, (size_t)88))
+        | !TEST(0, TEST_int_lt((size_t)88, (size_t)30))
+        | !TEST(1, TEST_int_le((size_t)30, (size_t)88))
+        | !TEST(1, TEST_int_le((size_t)33, (size_t)33))
+        | !TEST(0, TEST_int_le((size_t)88, (size_t)30))
+        | !TEST(1, TEST_int_gt((size_t)52, (size_t)33))
+        | !TEST(0, TEST_int_gt((size_t)33, (size_t)52))
+        | !TEST(1, TEST_int_ge((size_t)52, (size_t)33))
+        | !TEST(1, TEST_int_ge((size_t)38, (size_t)38))
+        | !TEST(0, TEST_int_ge((size_t)33, (size_t)52)))
+        goto err;
     return 1;
 
 err:
@@ -186,20 +198,21 @@ static int test_pointer(void)
     int x = 0;
     char y = 1;
 
-    C(err, 1, TEST_ptr(&y));
-    C(err, 0, TEST_ptr(NULL));
-    C(err, 0, TEST_ptr_null(&y));
-    C(err, 1, TEST_ptr_null(NULL));
-    C(err, 1, TEST_ptr_eq(NULL, NULL));
-    C(err, 0, TEST_ptr_eq(NULL, &y));
-    C(err, 0, TEST_ptr_eq(&y, NULL));
-    C(err, 0, TEST_ptr_eq(&y, &x));
-    C(err, 1, TEST_ptr_eq(&x, &x));
-    C(err, 0, TEST_ptr_ne(NULL, NULL));
-    C(err, 1, TEST_ptr_ne(NULL, &y));
-    C(err, 1, TEST_ptr_ne(&y, NULL));
-    C(err, 1, TEST_ptr_ne(&y, &x));
-    C(err, 0, TEST_ptr_ne(&x, &x));
+    if (!TEST(1, TEST_ptr(&y))
+        | !TEST(0, TEST_ptr(NULL))
+        | !TEST(0, TEST_ptr_null(&y))
+        | !TEST(1, TEST_ptr_null(NULL))
+        | !TEST(1, TEST_ptr_eq(NULL, NULL))
+        | !TEST(0, TEST_ptr_eq(NULL, &y))
+        | !TEST(0, TEST_ptr_eq(&y, NULL))
+        | !TEST(0, TEST_ptr_eq(&y, &x))
+        | !TEST(1, TEST_ptr_eq(&x, &x))
+        | !TEST(0, TEST_ptr_ne(NULL, NULL))
+        | !TEST(1, TEST_ptr_ne(NULL, &y))
+        | !TEST(1, TEST_ptr_ne(&y, NULL))
+        | !TEST(1, TEST_ptr_ne(&y, &x))
+        | !TEST(0, TEST_ptr_ne(&x, &x)))
+        goto err;
     return 1;
 
 err:
@@ -208,10 +221,11 @@ err:
 
 static int test_bool(void)
 {
-    C(err, 0, TEST_true(0));
-    C(err, 1, TEST_true(1));
-    C(err, 1, TEST_false(0));
-    C(err, 0, TEST_false(1));
+    if (!TEST(0, TEST_true(0))
+        | !TEST(1, TEST_true(1))
+        | !TEST(1, TEST_false(0))
+        | !TEST(0, TEST_false(1)))
+        goto err;
     return 1;
 
 err:
@@ -221,14 +235,16 @@ err:
 static int test_string(void)
 {
     static char buf[] = "abc";
-    C(err, 1, TEST_str_eq(NULL, NULL));
-    C(err, 1, TEST_str_eq("abc", buf));
-    C(err, 0, TEST_str_eq("abc", NULL));
-    C(err, 0, TEST_str_eq(NULL, buf));
-    C(err, 0, TEST_str_ne(NULL, NULL));
-    C(err, 0, TEST_str_ne("abc", buf));
-    C(err, 1, TEST_str_ne("abc", NULL));
-    C(err, 1, TEST_str_ne(NULL, buf));
+
+    if (!TEST(1, TEST_str_eq(NULL, NULL))
+        | !TEST(1, TEST_str_eq("abc", buf))
+        | !TEST(0, TEST_str_eq("abc", NULL))
+        | !TEST(0, TEST_str_eq(NULL, buf))
+        | !TEST(0, TEST_str_ne(NULL, NULL))
+        | !TEST(0, TEST_str_ne("abc", buf))
+        | !TEST(1, TEST_str_ne("abc", NULL))
+        | !TEST(1, TEST_str_ne(NULL, buf)))
+        goto err;
     return 1;
 
 err:
@@ -238,19 +254,30 @@ err:
 static int test_memory(void)
 {
     static char buf[] = "xyz";
-    C(err, 1, TEST_mem_eq(NULL, 0, NULL, 0));
-    C(err, 1, TEST_mem_eq(NULL, 1, NULL, 2));
-    C(err, 0, TEST_mem_eq(NULL, 0, "xyz", 3));
-    C(err, 0, TEST_mem_eq(NULL, 0, "", 0));
-    C(err, 0, TEST_mem_eq("xyz", 3, NULL, 0));
-    C(err, 0, TEST_mem_eq("xyz", 3, buf, sizeof(buf)));
-    C(err, 1, TEST_mem_eq("xyz", 4, buf, sizeof(buf)));
+
+    if (!TEST(1, TEST_mem_eq(NULL, 0, NULL, 0))
+        | !TEST(1, TEST_mem_eq(NULL, 1, NULL, 2))
+        | !TEST(0, TEST_mem_eq(NULL, 0, "xyz", 3))
+        | !TEST(0, TEST_mem_eq(NULL, 0, "", 0))
+        | !TEST(0, TEST_mem_eq("xyz", 3, NULL, 0))
+        | !TEST(0, TEST_mem_eq("xyz", 3, buf, sizeof(buf)))
+        | !TEST(1, TEST_mem_eq("xyz", 4, buf, sizeof(buf))))
+        goto err;
     return 1;
 
 err:
     return 0;
 }
 
+static int test_memory_overflow(void)
+{
+    /* Verify that the memory printing overflows without walking the stack */
+    const char *p = "1234567890123456789012345678901234567890123456789012";
+    const char *q = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
+
+    return TEST(0, TEST_mem_eq(p, strlen(p), q, strlen(q)));
+}
+
 static int test_messages(void)
 {
     TEST_info("This is an %s message.", "info");
@@ -326,6 +353,7 @@ void register_tests(void)
     ADD_TEST(test_bool);
     ADD_TEST(test_string);
     ADD_TEST(test_memory);
+    ADD_TEST(test_memory_overflow);
     ADD_TEST(test_messages);
     ADD_TEST(test_single_eval);
 }
diff --git a/test/testutil/tests.c b/test/testutil/tests.c
index 19a366f34c..057ad22b37 100644
--- a/test/testutil/tests.c
+++ b/test/testutil/tests.c
@@ -15,7 +15,7 @@
 #include "../../e_os.h"
 
 /* The size of memory buffers to display on failure */
-#define MEM_BUFFER_SIZE     (21)
+#define MEM_BUFFER_SIZE     (33)
 
 /*
  * A common routine to output test failure messages.  Generally this should not
@@ -267,23 +267,35 @@ int test_strn_ne(const char *file, int line, const char *st1, const char *st2,
 
 /*
  * We could use OPENSSL_buf2hexstr() to do this but trying to allocate memory
- * in a failure state isn't generally a great idea.
+ * in a failure state isn't generally a great idea and if it fails, we want a
+ * fall back position using caller supplied buffers.
+ *
+ * If the return value is different from the buffer supplied, it needs to be
+ * freed by the caller.
  */
-static const char *print_mem_maybe_null(const void *s, size_t n,
-                                        char out[MEM_BUFFER_SIZE])
+static char *print_mem_maybe_null(const void *s, size_t n,
+                                  char outbuf[MEM_BUFFER_SIZE])
 {
     size_t i;
     const unsigned char *p = (const unsigned char *)s;
-    int pad = 2*n >= MEM_BUFFER_SIZE;
+    char *out = outbuf;
+    int pad = 2 * n >= MEM_BUFFER_SIZE;
 
     if (s == NULL)
-        return "(NULL)";
-    if (pad)
-        n = MEM_BUFFER_SIZE-4;
-    
-    for (i=0; i<2*n; i++) {
-        unsigned char c = (i & 1) != 0 ? p[i / 2] & 15 : p[i / 2] >> 4;
-        out[i] = "0123456789abcdef"[c];
+        return strcpy(outbuf, "(NULL)");
+    if (pad) {
+        if ((out = OPENSSL_malloc(2 * n + 1)) == NULL) {
+            out = outbuf;
+            n = (MEM_BUFFER_SIZE - 4) / 2;
+        } else {
+            pad = 0;
+        }
+    }
+
+    for (i = 0; i < 2 * n; ) {
+        const unsigned char c = *p++;
+        out[i++] = "0123456789abcdef"[c >> 4];
+        out[i++] = "0123456789abcdef"[c & 15];
     }
     if (pad) {
         out[i++] = '.';
@@ -291,7 +303,7 @@ static const char *print_mem_maybe_null(const void *s, size_t n,
         out[i++] = '.';
     }
     out[i] = '\0';
-        
+
     return out;
 }
 
@@ -302,18 +314,17 @@ int test_mem_eq(const char *file, int line, const char *st1, const char *st2,
 
     if (s1 == NULL && s2 == NULL)
         return 1;
-    if (n1 != n2) {
-        test_fail_message(NULL, file, line, "memory",
-                          "size mismatch %s %s [%zu] != %s %s [%zu]",
-                          st1, print_mem_maybe_null(s1, n1, b1), n1,
-                          st2, print_mem_maybe_null(s2, n2, b2), n2);
-        return 0;
-    }
-    if (s1 == NULL || s2 == NULL || memcmp(s1, s2, n1) != 0) {
+    if (n1 != n2 || s1 == NULL || s2 == NULL || memcmp(s1, s2, n1) != 0) {
+        char *m1 = print_mem_maybe_null(s1, n1, b1);
+        char *m2 = print_mem_maybe_null(s2, n2, b2);
+
         test_fail_message(NULL, file, line, "memory",
-                          "%s %s [%zu] != %s %s [%zu]",
-                          st1, print_mem_maybe_null(s1, n1, b1), n1,
-                          st2, print_mem_maybe_null(s2, n2, b2), n2);
+                          "%s %s [%zu] == %s %s [%zu]",
+                          st1, m1, n1, st2, m2, n2);
+        if (m1 != b1)
+            OPENSSL_free(m1);
+        if (m2 != b2)
+            OPENSSL_free(m2);
         return 0;
     }
     return 1;
@@ -325,14 +336,20 @@ int test_mem_ne(const char *file, int line, const char *st1, const char *st2,
     char b1[MEM_BUFFER_SIZE], b2[MEM_BUFFER_SIZE];
 
     if ((s1 == NULL) ^ (s2 == NULL))
-      return 1;
+        return 1;
     if (n1 != n2)
         return 1;
     if (s1 == NULL || memcmp(s1, s2, n1) == 0) {
+        char *m1 = print_mem_maybe_null(s1, n1, b1);
+        char *m2 = print_mem_maybe_null(s2, n2, b2);
+
         test_fail_message(NULL, file, line, "memory",
                           "%s %s [%zu] != %s %s [%zu]",
-                          st1, print_mem_maybe_null(s1, n1, b1), n1,
-                          st2, print_mem_maybe_null(s2, n2, b2), n2);
+                          st1, m1, n1, st2, m2, n2);
+        if (m1 != b1)
+            OPENSSL_free(m1);
+        if (m2 != b2)
+            OPENSSL_free(m2);
         return 0;
     }
     return 1;