[gimp] file-gif-load: fix heap corruption and buffer overflow (CVE-2011-2896)
- From: Nils Philippsen <nphilipp src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [gimp] file-gif-load: fix heap corruption and buffer overflow (CVE-2011-2896)
- Date: Fri, 12 Aug 2011 11:54:26 +0000 (UTC)
commit 376ad788c1a1c31d40f18494889c383f6909ebfc
Author: Nils Philippsen <nils redhat com>
Date: Thu Aug 4 12:51:42 2011 +0200
file-gif-load: fix heap corruption and buffer overflow (CVE-2011-2896)
plug-ins/common/file-gif-load.c | 15 +++++++++------
1 files changed, 9 insertions(+), 6 deletions(-)
---
diff --git a/plug-ins/common/file-gif-load.c b/plug-ins/common/file-gif-load.c
index 81f3bd0..c91e7aa 100644
--- a/plug-ins/common/file-gif-load.c
+++ b/plug-ins/common/file-gif-load.c
@@ -713,7 +713,8 @@ LZWReadByte (FILE *fd,
static gint firstcode, oldcode;
static gint clear_code, end_code;
static gint table[2][(1 << MAX_LZW_BITS)];
- static gint stack[(1 << (MAX_LZW_BITS)) * 2], *sp;
+#define STACK_SIZE ((1 << (MAX_LZW_BITS)) * 2)
+ static gint stack[STACK_SIZE], *sp;
gint i;
if (just_reset_LZW)
@@ -788,7 +789,7 @@ LZWReadByte (FILE *fd,
return firstcode & 255;
}
- else if (code == end_code)
+ else if (code == end_code || code > max_code)
{
gint count;
guchar buf[260];
@@ -807,13 +808,14 @@ LZWReadByte (FILE *fd,
incode = code;
- if (code >= max_code)
+ if (code == max_code)
{
- *sp++ = firstcode;
+ if (sp < &(stack[STACK_SIZE]))
+ *sp++ = firstcode;
code = oldcode;
}
- while (code >= clear_code)
+ while (code >= clear_code && sp < &(stack[STACK_SIZE]))
{
*sp++ = table[1][code];
if (code == table[0][code])
@@ -824,7 +826,8 @@ LZWReadByte (FILE *fd,
code = table[0][code];
}
- *sp++ = firstcode = table[1][code];
+ if (sp < &(stack[STACK_SIZE]))
+ *sp++ = firstcode = table[1][code];
if ((code = max_code) < (1 << MAX_LZW_BITS))
{
[
Date Prev][
Date Next] [
Thread Prev][
Thread Next]
[
Thread Index]
[
Date Index]
[
Author Index]