[FFmpeg-devel] [PATCH 1/1][NO NOT APPLY] Allocation NULL check fuzzing tool

[Derek Buitenhuis]

Signed-off-by: Derek Buitenhuis <derek.buitenhuis at gmail.com>
---
 libavutil/mem.c           |  4 ++-
 libavutil/posixmemalign.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 89 insertions(+), 1 deletion(-)
 create mode 100644 libavutil/posixmemalign.c

diff --git a/libavutil/mem.c b/libavutil/mem.c
index 6ad409daf4..0d9ab3d230 100644
--- a/libavutil/mem.c
+++ b/libavutil/mem.c
@@ -43,6 +43,8 @@
 #include "intreadwrite.h"
 #include "mem.h"
 
+#include "posixmemalign.c"
+
 #ifdef MALLOC_PREFIX
 
 #define malloc         AV_JOIN(MALLOC_PREFIX, malloc)
@@ -84,7 +86,7 @@ void *av_malloc(size_t size)
 
 #if HAVE_POSIX_MEMALIGN
     if (size) //OS X on SDK 10.6 has a broken posix_memalign implementation
-    if (posix_memalign(&ptr, ALIGN, size))
+    if (my_posix_memalign(&ptr, ALIGN, size))
         ptr = NULL;
 #elif HAVE_ALIGNED_MALLOC
     ptr = _aligned_malloc(size, ALIGN);
diff --git a/libavutil/posixmemalign.c b/libavutil/posixmemalign.c
new file mode 100644
index 0000000000..b1970add7b
--- /dev/null
+++ b/libavutil/posixmemalign.c
@@ -0,0 +1,86 @@
+/*
+ * posix_memalign wrapper with random failurres
+ *
+ * Copyright (c) 2013, Derek Buitenhuis
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#define _GNU_SOURCE
+
+#include <dlfcn.h>
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <backtrace.h>
+
+static void errprint(void *data, const char *msg, int errnum)
+{
+    fprintf(stderr, "ERROR: %s.\n", msg);
+}
+
+static int stackprint(void *data, uintptr_t pc, const char *filename, int lineno, const char *function)
+{
+    fprintf(stderr, "%s:%d in %s\n", function, lineno, filename);
+    return 0;
+}
+
+static int my_posix_memalign(void **memptr, size_t alignment, size_t size)
+{
+    static time_t   seed      = 0;
+    static int      prob      = 0;
+    static uint64_t iteration = 0;
+    int ret;
+
+    struct backtrace_state *state = backtrace_create_state("", 1, errprint, NULL);
+
+    if (state == NULL)
+        abort();
+
+    if (!seed) {
+        char *usertime = getenv("MALLOC_SEED");
+
+        if (!usertime)
+            seed = time(NULL);
+        else
+            seed = atoi(usertime);
+
+        srand(seed);
+    }
+
+    if (!prob) {
+        char *userprob = getenv("MALLOC_FAILPROB");
+
+        if (!userprob)
+            prob = 10000;
+        else
+            prob = atoi(userprob);
+    }
+
+    if (!(rand() % prob)) {
+        fprintf(stderr,
+                "\nFAILED. Iteration = %"PRId64", Seed = %lld.\n\n",
+                iteration, (long long) seed);
+        backtrace_full(state, 0, stackprint, errprint, NULL);
+        ret = 0;
+    } else {
+        ret = posix_memalign(memptr, alignment, size);
+    }
+
+    iteration++;
+
+    return ret;
+}
-- 
2.15.0