Module Name: xsrc
Committed By: joerg
Date: Tue Aug 16 13:57:30 UTC 2011
Modified Files:
xsrc/external/mit/libXfont/dist/src/fontfile: decompress.c
xsrc/xfree/xc/lib/font/fontfile: decompress.c
Log Message:
Do proper input validation. Allow decompressing all input streams.
To generate a diff of this commit:
cvs rdiff -u -r1.2 -r1.3 \
xsrc/external/mit/libXfont/dist/src/fontfile/decompress.c
cvs rdiff -u -r1.1.1.4 -r1.2 xsrc/xfree/xc/lib/font/fontfile/decompress.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: xsrc/external/mit/libXfont/dist/src/fontfile/decompress.c
diff -u xsrc/external/mit/libXfont/dist/src/fontfile/decompress.c:1.2 xsrc/external/mit/libXfont/dist/src/fontfile/decompress.c:1.3
--- xsrc/external/mit/libXfont/dist/src/fontfile/decompress.c:1.2 Mon Aug 15 21:19:27 2011
+++ xsrc/external/mit/libXfont/dist/src/fontfile/decompress.c Tue Aug 16 13:57:30 2011
@@ -99,7 +99,7 @@
#define FIRST 257 /* first free entry */
#define CLEAR 256 /* table clear output code */
-#define STACK_SIZE 8192
+#define STACK_SIZE 65300
typedef struct _compressedFILE {
BufFilePtr file;
@@ -180,14 +180,12 @@
file->tab_suffix[code] = (char_type) code;
}
file->free_ent = ((file->block_compress) ? FIRST : 256 );
+ file->oldcode = -1;
file->clear_flg = 0;
file->offset = 0;
file->size = 0;
file->stackp = file->de_stack;
bzero(file->buf, BITS);
- file->finchar = file->oldcode = getcode (file);
- if (file->oldcode != -1)
- *file->stackp++ = file->finchar;
return BufFileCreate ((char *) file,
BufCompressedFill,
0,
@@ -232,9 +230,6 @@
if (buf == bufend)
break;
- if (oldcode == -1)
- break;
-
code = getcode (file);
if (code == -1)
break;
@@ -243,26 +238,34 @@
for ( code = 255; code >= 0; code-- )
file->tab_prefix[code] = 0;
file->clear_flg = 1;
- file->free_ent = FIRST - 1;
- if ( (code = getcode (file)) == -1 ) /* O, untimely death! */
- break;
+ file->free_ent = FIRST;
+ oldcode = -1;
+ continue;
}
incode = code;
/*
* Special case for KwKwK string.
*/
if ( code >= file->free_ent ) {
+ if ( code > file->free_ent || oldcode == -1 ) {
+ /* Bad stream. */
+ return BUFFILEEOF;
+ }
*stackp++ = finchar;
code = oldcode;
}
-
+ /*
+ * The above condition ensures that code < free_ent.
+ * The construction of tab_prefixof in turn guarantees that
+ * each iteration decreases code and therefore stack usage is
+ * bound by 1 << BITS - 256.
+ */
+
/*
* Generate output characters in reverse order
*/
while ( code >= 256 )
{
- if (stackp - de_stack >= STACK_SIZE - 1)
- return BUFFILEEOF;
*stackp++ = file->tab_suffix[code];
code = file->tab_prefix[code];
}
@@ -272,7 +275,7 @@
/*
* Generate the new entry.
*/
- if ( (code=file->free_ent) < file->maxmaxcode ) {
+ if ( (code=file->free_ent) < file->maxmaxcode && oldcode != -1) {
file->tab_prefix[code] = (unsigned short)oldcode;
file->tab_suffix[code] = finchar;
file->free_ent = code+1;
Index: xsrc/xfree/xc/lib/font/fontfile/decompress.c
diff -u xsrc/xfree/xc/lib/font/fontfile/decompress.c:1.1.1.4 xsrc/xfree/xc/lib/font/fontfile/decompress.c:1.2
--- xsrc/xfree/xc/lib/font/fontfile/decompress.c:1.1.1.4 Sat Jan 19 14:58:56 2002
+++ xsrc/xfree/xc/lib/font/fontfile/decompress.c Tue Aug 16 13:57:30 2011
@@ -96,7 +96,7 @@
#define FIRST 257 /* first free entry */
#define CLEAR 256 /* table clear output code */
-#define STACK_SIZE 8192
+#define STACK_SIZE 65300
typedef struct _compressedFILE {
BufFilePtr file;
@@ -177,14 +177,12 @@
file->tab_suffix[code] = (char_type) code;
}
file->free_ent = ((file->block_compress) ? FIRST : 256 );
+ file->oldcode = -1;
file->clear_flg = 0;
file->offset = 0;
file->size = 0;
file->stackp = file->de_stack;
bzero(file->buf, BITS);
- file->finchar = file->oldcode = getcode (file);
- if (file->oldcode != -1)
- *file->stackp++ = file->finchar;
return BufFileCreate ((char *) file,
BufCompressedFill,
0,
@@ -229,9 +227,6 @@
if (buf == bufend)
break;
- if (oldcode == -1)
- break;
-
code = getcode (file);
if (code == -1)
break;
@@ -240,19 +235,29 @@
for ( code = 255; code >= 0; code-- )
file->tab_prefix[code] = 0;
file->clear_flg = 1;
- file->free_ent = FIRST - 1;
- if ( (code = getcode (file)) == -1 ) /* O, untimely death! */
- break;
+ file->free_ent = FIRST;
+ oldcode = -1;
+ continue;
}
incode = code;
/*
* Special case for KwKwK string.
*/
if ( code >= file->free_ent ) {
+ if ( code > file->free_ent || oldcode == -1 ) {
+ /* Bad stream. */
+ return BUFFILEEOF;
+ }
*stackp++ = finchar;
code = oldcode;
}
-
+ /*
+ * The above condition ensures that code < free_ent.
+ * The construction of tab_prefixof in turn guarantees that
+ * each iteration decreases code and therefore stack usage is
+ * bound by 1 << BITS - 256.
+ */
+
/*
* Generate output characters in reverse order
*/
@@ -267,7 +272,7 @@
/*
* Generate the new entry.
*/
- if ( (code=file->free_ent) < file->maxmaxcode ) {
+ if ( (code=file->free_ent) < file->maxmaxcode && oldcode != -1) {
file->tab_prefix[code] = (unsigned short)oldcode;
file->tab_suffix[code] = finchar;
file->free_ent = code+1;
