diff -urN xzgv-0.8/ChangeLog xzgv/ChangeLog
--- xzgv-0.8/ChangeLog Tue Sep 16 15:08:42 2003
+++ xzgv/ChangeLog Wed Dec 15 03:30:46 2004
@@ -1,3 +1,13 @@
+2004-11-03 Russell Marks <russell.marks@ntlworld.com>
+
+ * Added width/height limits to all native picture readers. This is
+ a crude (albeit effective) fix for heap overflow bugs - there may
+ yet be more subtle problems, but I can't really fix them until I
+ know they're there. :-) Thanks to Luke Macken for letting me know
+ about the heap overflow problems (in zgv). I suppose I should also
+ thank "infamous41md" for publishing the original advisory/exploit
+ (again for zgv), even if he didn't bother emailing me or anything.
+
2003-09-16 Russell Marks <russell.marks@ntlworld.com>
* Version 0.8.
diff -urN xzgv-0.8/src/Makefile xzgv/src/Makefile
--- xzgv-0.8/src/Makefile Tue Jan 1 05:37:45 2002
+++ xzgv/src/Makefile Wed Dec 15 03:30:46 2004
@@ -84,18 +84,19 @@
logo.o: logo.c logodata.h
logoconv.o: logoconv.c
main.o: main.c backend.h readmrf.h readgif.h readpng.h readjpeg.h \
- readtiff.h resizepic.h rcfile.h filedetails.h gotodir.h updatetn.h \
- confirm.h misc.h copymove.h rename.h help.h dir_icon.xpm \
+ readtiff.h readprf.h resizepic.h rcfile.h filedetails.h gotodir.h \
+ updatetn.h confirm.h misc.h copymove.h rename.h help.h dir_icon.xpm \
dir_icon_small.xpm file_icon.xpm file_icon_small.xpm logo.h \
icon-48.xpm main.h
misc.o: misc.c misc.h
rcfile.o: rcfile.c getopt.h rcfile.h rcfile_opt.h rcfile_var.h \
rcfile_short.h
-readgif.o: readgif.c readgif.h
-readjpeg.o: readjpeg.c rcfile.h readjpeg.h
-readmrf.o: readmrf.c readmrf.h
+readgif.o: readgif.c reader.h readgif.h
+readjpeg.o: readjpeg.c rcfile.h reader.h readjpeg.h
+readmrf.o: readmrf.c reader.h readmrf.h
readpng.o: readpng.c readpng.h
-readtiff.o: readtiff.c readtiff.h
+readprf.o: readprf.c reader.h readprf.h
+readtiff.o: readtiff.c reader.h readtiff.h
rename.o: rename.c backend.h main.h rename.h
resizepic.o: resizepic.c resizepic.h
updatetn.o: updatetn.c backend.h main.h rcfile.h dither.h resizepic.h \
diff -urN xzgv-0.8/src/reader.h xzgv/src/reader.h
--- xzgv-0.8/src/reader.h Thu Jan 1 01:00:00 1970
+++ xzgv/src/reader.h Wed Dec 15 03:30:46 2004
@@ -0,0 +1,15 @@
+/* xzgv 0.8 - picture viewer for X, with file selector.
+ * Copyright (C) 1999-2004 Russell Marks. See main.c for license details.
+ *
+ * reader.h
+ */
+
+/* range check on width and height as a crude way of avoiding overflows
+ * when calling malloc/calloc. 32767 is the obvious limit to use given that
+ * xzgv effectively imposes such a limit anyway.
+ * Adds an extra 2 to height for max-height check, partly to reflect what
+ * the check in zgv does but also to allow for readtiff.c allocating an
+ * extra line (so at least an extra 1 would have been needed in any case).
+ */
+#define WH_MAX 32767
+#define WH_BAD(w,h) ((w)<=0 || (w)>WH_MAX || (h)<=0 || ((h)+2)>WH_MAX)
diff -urN xzgv-0.8/src/readgif.c xzgv/src/readgif.c
--- xzgv-0.8/src/readgif.c Sun Mar 3 04:34:32 2002
+++ xzgv/src/readgif.c Wed Dec 15 03:30:46 2004
@@ -8,6 +8,7 @@
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
+#include "reader.h"
#include "readgif.h"
@@ -103,7 +104,7 @@
if(local_colour_map) readcolmap(in);
- if((image=malloc(width*height*3))==NULL)
+ if(WH_BAD(width,height) || (image=malloc(width*height*3))==NULL)
{
fclose(in);
return(0);
diff -urN xzgv-0.8/src/readjpeg.c xzgv/src/readjpeg.c
--- xzgv-0.8/src/readjpeg.c Tue Sep 16 12:52:04 2003
+++ xzgv/src/readjpeg.c Wed Dec 15 03:30:46 2004
@@ -13,6 +13,7 @@
#include <jpeglib.h>
#include "rcfile.h"
+#include "reader.h"
#include "readjpeg.h"
@@ -265,7 +266,7 @@
/* this one shouldn't hurt */
cinfo.do_block_smoothing=FALSE;
-if((*imagep=image=malloc(width*height*3))==NULL)
+if(WH_BAD(width,height) || (*imagep=image=malloc(width*height*3))==NULL)
longjmp(jerr.setjmp_buffer,1);
jpeg_start_decompress(&cinfo);
diff -urN xzgv-0.8/src/readmrf.c xzgv/src/readmrf.c
--- xzgv-0.8/src/readmrf.c Sat Oct 7 14:26:55 2000
+++ xzgv/src/readmrf.c Wed Dec 15 03:30:46 2004
@@ -7,6 +7,7 @@
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
+#include "reader.h"
#include "readmrf.h"
@@ -91,7 +92,8 @@
w64=(w+63)/64;
h64=(h+63)/64;
-if((*bmap=malloc(w*h*3))==NULL ||
+if(WH_BAD(w64*64,h64*64) || WH_BAD(w,h) ||
+ (*bmap=malloc(w*h*3))==NULL ||
(image=calloc(w64*h64*64*64,1))==NULL)
{
if(*bmap) free(*bmap),*bmap=NULL;
diff -urN xzgv-0.8/src/readpng.c xzgv/src/readpng.c
--- xzgv-0.8/src/readpng.c Thu Jul 10 16:13:43 2003
+++ xzgv/src/readpng.c Wed Dec 15 03:32:46 2004
@@ -16,6 +16,7 @@
#include <stdlib.h>
#include <png.h>
#include <setjmp.h> /* after png.h to avoid horrible thing in pngconf.h */
+#include "reader.h"
#include "readpng.h"
@@ -129,7 +130,8 @@
}
/* allocate image memory */
-if((*theimageptr=theimage=malloc(width*height*3))==NULL)
+if(WH_BAD(width,height) ||
+ (*theimageptr=theimage=malloc(width*height*3))==NULL)
{
png_read_end(png_ptr,info_ptr);
png_destroy_read_struct(&png_ptr,&info_ptr,NULL);
diff -urN xzgv-0.8/src/readprf.c xzgv/src/readprf.c
--- xzgv-0.8/src/readprf.c Mon Apr 9 19:08:19 2001
+++ xzgv/src/readprf.c Wed Dec 15 03:30:46 2004
@@ -7,6 +7,7 @@
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
+#include "reader.h"
#include "readprf.h"
#define squaresize 64
@@ -164,7 +165,7 @@
bytepp=1;
n=width*squaresize;
-if((planebuf[0]=calloc(n,planes))==NULL)
+if(WH_BAD(width,height) || (planebuf[0]=calloc(n,planes))==NULL)
{
fclose(in);
return(0);
@@ -173,6 +174,7 @@
for(f=1;f<planes;f++)
planebuf[f]=planebuf[f-1]+n;
+/* width/height already checked above */
if((*theimageptr=malloc(width*height*3))==NULL)
{
free(planebuf[0]);
diff -urN xzgv-0.8/src/readtiff.c xzgv/src/readtiff.c
--- xzgv-0.8/src/readtiff.c Thu Dec 28 03:20:55 2000
+++ xzgv/src/readtiff.c Wed Dec 15 03:30:46 2004
@@ -11,7 +11,7 @@
#include <setjmp.h>
#include <sys/file.h> /* for open et al */
#include <tiffio.h>
-
+#include "reader.h"
#include "readtiff.h"
@@ -36,7 +36,8 @@
* spare for the flip afterwards.
*/
numpix=width*height;
-if((image=malloc(numpix*sizeof(uint32)+width*3))==NULL)
+if(WH_BAD(width,height) ||
+ (image=malloc(numpix*sizeof(uint32)+width*3))==NULL)
{
TIFFClose(in);
return(0);