| From 042421e9e3d266ad0bb7805132041ef51ad3234d Mon Sep 17 00:00:00 2001 |
| From: Adrian Johnson <ajohnson@redneon.com> |
| Date: Wed, 16 Aug 2017 22:52:35 -0400 |
| Subject: [PATCH] cairo: Fix CVE-2017-9814 |
| |
| The bug happens because in some scenarios the variable size can |
| have a value of 0 at line 1288. And malloc(0) is not returning |
| NULL as some people could expect: |
| |
| https://stackoverflow.com/questions/1073157/zero-size-malloc |
| |
| malloc(0) returns the smallest chunk possible. So the line 1290 |
| with the return is not execute. And the execution continues with |
| an invalid map. |
| |
| Since the size is 0 the variable map is not initialized correctly |
| at load_trutype_table. So, later when the variable map is accessed |
| previous values from a freed chunk are used. This could allows an |
| attacker to control the variable map. |
| |
| This patch have not merge in upstream now. |
| |
| Upstream-Status: Backport [https://bugs.freedesktop.org/show_bug.cgi?id=101547] |
| CVE: CVE-2017-9814 |
| Signed-off-by: Dengke Du <dengke.du@windriver.com> |
| --- |
| src/cairo-truetype-subset.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| diff --git a/src/cairo-truetype-subset.c b/src/cairo-truetype-subset.c |
| index e3449a0..f77d11c 100644 |
| --- a/src/cairo-truetype-subset.c |
| +++ b/src/cairo-truetype-subset.c |
| @@ -1285,7 +1285,7 @@ _cairo_truetype_reverse_cmap (cairo_scaled_font_t *scaled_font, |
| return CAIRO_INT_STATUS_UNSUPPORTED; |
| |
| size = be16_to_cpu (map->length); |
| - map = malloc (size); |
| + map = _cairo_malloc (size); |
| if (unlikely (map == NULL)) |
| return _cairo_error (CAIRO_STATUS_NO_MEMORY); |
| |
| -- |
| 2.8.1 |
| |