3 files changed, 79 insertions, 23 deletions
diff --git a/src/lib/gssapi/generic/gssapiP_generic.h b/src/lib/gssapi/generic/gssapiP_generic.h
index 1124c51e59..3fb0c76227 100644
--- a/src/lib/gssapi/generic/gssapiP_generic.h
+++ b/src/lib/gssapi/generic/gssapiP_generic.h
@@ -278,7 +278,7 @@ k5buf_to_gss(OM_uint32 *minor,
     OM_uint32 status = GSS_S_COMPLETE;
     char *bp = krb5int_buf_data(input_k5buf);
     output_buffer->length = krb5int_buf_len(input_k5buf)+1;
-#ifdef _WIN32
+#if defined(_WIN32) || defined(DEBUG_GSSALLOC)
     if (output_buffer->length > 0) {
         output_buffer->value = gssalloc_malloc(output_buffer->length);
         if (output_buffer->value) {
diff --git a/src/lib/gssapi/generic/gssapi_alloc.h b/src/lib/gssapi/generic/gssapi_alloc.h
index 9c0f340b11..9a5cd9892c 100644
--- a/src/lib/gssapi/generic/gssapi_alloc.h
+++ b/src/lib/gssapi/generic/gssapi_alloc.h
@@ -9,54 +9,110 @@
 
 #ifdef _WIN32
 #include "winbase.h"
-#define USE_HEAPALLOC 1
-#else
-#define USE_HEAPALLOC 0
 #endif
 #include <string.h>
 
+#if defined(_WIN32)
+
 static inline void
-gssalloc_free(void * value)
+gssalloc_free(void *value)
 {
-    if (value) {
-#if USE_HEAPALLOC
+    if (value)
         HeapFree(GetProcessHeap(), 0, value);
-#else
-        free(value);
-#endif
-    }
 }
 
 static inline void *
 gssalloc_malloc(size_t size)
 {
-#if USE_HEAPALLOC
     return HeapAlloc(GetProcessHeap(), 0, size);
-#else
-    return malloc(size);
-#endif
 }
 
 static inline void *
 gssalloc_calloc(size_t count, size_t size)
 {
-#if USE_HEAPALLOC
     return HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, count * size);
-#else
-    return calloc(count, size);
-#endif
 }
 
 static inline void *
 gssalloc_realloc(void *value, size_t size)
 {
-#if USE_HEAPALLOC
     return HeapReAlloc(GetProcessHeap(), 0, value, size);
-#else
+}
+
+#elif defined(DEBUG_GSSALLOC)
+
+/* Be deliberately incompatible with malloc and free, to allow us to detect
+ * mismatched malloc/gssalloc usage on Unix. */
+
+static inline void
+gssalloc_free(void *value)
+{
+    char *p = (char *)value - 8;
+
+    if (value == NULL)
+        return;
+    if (memcmp(p, "gssalloc", 8) != 0)
+        abort();
+    free(p);
+}
+
+static inline void *
+gssalloc_malloc(size_t size)
+{
+    char *p = calloc(size + 8, 1);
+
+    memcpy(p, "gssalloc", 8);
+    return p + 8;
+}
+
+static inline void *
+gssalloc_calloc(size_t count, size_t size)
+{
+    return gssalloc_malloc(count * size);
+}
+
+static inline void *
+gssalloc_realloc(void *value, size_t size)
+{
+    char *p = (char *)value - 8;
+
+    if (value == NULL)
+        return gssalloc_malloc(size);
+    if (memcmp(p, "gssalloc", 8) != 0)
+        abort();
+    return (char *)realloc(p, size) + 8;
+}
+
+#else /* not _WIN32 or DEBUG_GSSALLOC */
+
+/* Normal Unix case, just use free/malloc/calloc/realloc. */
+
+static inline void
+gssalloc_free(void *value)
+{
+    free(value);
+}
+
+static inline void *
+gssalloc_malloc(size_t size)
+{
+    return malloc(size);
+}
+
+static inline void *
+gssalloc_calloc(size_t count, size_t size)
+{
+    return calloc(count, size);
+}
+
+static inline void *
+gssalloc_realloc(void *value, size_t size)
+{
     return realloc(value, size);
-#endif
 }
 
+#endif /* not _WIN32 or DEBUG_GSSALLOC */
+
 static inline char *
 gssalloc_strdup(const char *str)
 {
diff --git a/src/lib/gssapi/krb5/gssapiP_krb5.h b/src/lib/gssapi/krb5/gssapiP_krb5.h
index 56b025b767..8785ec981f 100644
--- a/src/lib/gssapi/krb5/gssapiP_krb5.h
+++ b/src/lib/gssapi/krb5/gssapiP_krb5.h
@@ -1204,7 +1204,7 @@ data_to_gss(krb5_data *input_k5data, gss_buffer_t output_buffer)
 {
     krb5_error_code code = 0;
     output_buffer->length = input_k5data->length;
-#ifdef _WIN32
+#if defined(_WIN32) || defined(DEBUG_GSSALLOC)
     if (output_buffer->length > 0) {
         output_buffer->value = gssalloc_malloc(output_buffer->length);
         if (output_buffer->value)