From 69c93dd259daf8ff2eb5945eba1d9f811ad325b9 Mon Sep 17 00:00:00 2001
From: Ceyhun Alp <ceyhunalp@google.com>
Date: Thu, 26 Nov 2020 15:09:38 +0000
Subject: [PATCH] Change malloc to calloc. Randomize glyphs

---
 fuzzing/pdf_surface_fuzzer.c |  4 +---
 fuzzing/raster_fuzzer.c      |  2 +-
 fuzzing/text_glyphs_fuzzer.c | 18 +++++++-----------
 3 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/fuzzing/pdf_surface_fuzzer.c b/fuzzing/pdf_surface_fuzzer.c
index d6c698dc0..33cb0e08b 100644
--- a/fuzzing/pdf_surface_fuzzer.c
+++ b/fuzzing/pdf_surface_fuzzer.c
@@ -11,7 +11,6 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     cairo_t *cr;
     cairo_surface_t *surface;
     cairo_status_t status;
-    int flags;
 
     char *tmpfile = fuzzer_get_tmpfile(data, size);
     surface = cairo_pdf_surface_create(tmpfile, WIDTH_IN_POINTS, HEIGHT_IN_POINTS);
@@ -21,11 +20,10 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
         return 0;
     }
 
-    char *buf = (char *) malloc(size + 1);
+    char *buf = (char *) calloc(size + 1, sizeof(char));
     memcpy(buf, data, size);
     buf[size] = '\0';
 
-    flags = CAIRO_PDF_OUTLINE_FLAG_BOLD | CAIRO_PDF_OUTLINE_FLAG_OPEN;
     cairo_pdf_surface_set_metadata(surface, CAIRO_PDF_METADATA_TITLE, buf);
     cr = cairo_create(surface);
     cairo_tag_begin(cr, buf, NULL);
diff --git a/fuzzing/raster_fuzzer.c b/fuzzing/raster_fuzzer.c
index d8c53bbf5..797d4e7c1 100644
--- a/fuzzing/raster_fuzzer.c
+++ b/fuzzing/raster_fuzzer.c
@@ -40,7 +40,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     w = cairo_image_surface_get_width(surface);
     h = cairo_image_surface_get_height(surface);
 
-    char *buf = (char *) malloc(size + 1);
+    char *buf = (char *) calloc(size + 1, sizeof(char));
     memcpy(buf, data, size);
     buf[size] = '\0';
 
diff --git a/fuzzing/text_glyphs_fuzzer.c b/fuzzing/text_glyphs_fuzzer.c
index ae5586f75..60d752934 100644
--- a/fuzzing/text_glyphs_fuzzer.c
+++ b/fuzzing/text_glyphs_fuzzer.c
@@ -1,22 +1,18 @@
 #include <cairo.h>
 #include "fuzzer_temp_file.h"
 
+#define GLYPH_RANGE 9
+
 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+    if (size < GLYPH_RANGE) {
+        return 0;
+    }
     cairo_t *cr;
     cairo_surface_t *surface;
     cairo_status_t status;
     cairo_text_extents_t extents;
     cairo_text_cluster_t cluster;
 
-    // Taken from test/text-glyph-range.c
-    long int index[] = {
-        0, /* 'no matching glyph' */
-        0xffff, /* kATSDeletedGlyphCode */
-        0x1ffff, /* out of range */
-        -1L, /* out of range */
-        70, 68, 76, 85, 82 /* 'cairo' */
-    };
-
     char *tmpfile = fuzzer_get_tmpfile(data, size);
     surface = cairo_image_surface_create_from_png(tmpfile);
     status = cairo_surface_status(surface);
@@ -25,7 +21,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
         return 0;
     }
 
-    char *buf = (char *) malloc(size + 1);
+    char *buf = (char *) calloc(size + 1, sizeof(char));
     memcpy(buf, data, size);
     buf[size] = '\0';
 
@@ -36,7 +32,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     for (int i = 0; i < 9; i++) {
         // Taken from test/text-glyph-range.c
         cairo_glyph_t glyph = {
-            index[i], 10 * i, 25
+            (long int)data[i], 10 * i, 25
         };
         cairo_show_text_glyphs(cr, buf, size, &glyph, 1, &cluster, 1, 0);
     }