From b04cd19b76374ebce8f3326275bdfd7e9b9aeab5 Mon Sep 17 00:00:00 2001
From: Li Zhou
Date: Sun, 11 Feb 2018 15:03:21 +0800
Subject: [PATCH] Fixed bug #75571: Potential infinite loop in
gdImageCreateFromGifCtx
Due to a signedness confusion in `GetCode_` a corrupt GIF file can
trigger an infinite loop. Furthermore we make sure that a GIF without
any palette entries is treated as invalid *after* open palette entries
have been removed.
Upstream-Status: Backport
CVE: CVE-2018-5711
Signed-off-by: Li Zhou
---
ext/gd/libgd/gd_gif_in.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/ext/gd/libgd/gd_gif_in.c b/ext/gd/libgd/gd_gif_in.c
index 76ba152..7156e4b 100644
--- a/ext/gd/libgd/gd_gif_in.c
+++ b/ext/gd/libgd/gd_gif_in.c
@@ -261,10 +261,6 @@ terminated:
if (!im) {
return 0;
}
- if (!im->colorsTotal) {
- gdImageDestroy(im);
- return 0;
- }
/* Check for open colors at the end, so
we can reduce colorsTotal and ultimately
BitsPerPixel */
@@ -275,6 +271,10 @@ terminated:
break;
}
}
+ if (!im->colorsTotal) {
+ gdImageDestroy(im);
+ return 0;
+ }
return im;
}
/* }}} */
@@ -375,7 +375,7 @@ static int
GetCode_(gdIOCtx *fd, CODE_STATIC_DATA *scd, int code_size, int flag, int *ZeroDataBlockP)
{
int i, j, ret;
- unsigned char count;
+ int count;
if (flag) {
scd->curbit = 0;
--
1.9.1