1999.12.10 14:20 "libtiff problem (fwd)", by Tom Kacvinsky

Hi,

The following message is from Han The Thanh (who is Vietnamese, so his given name is Thanh). Some of you may know about pdftex, it is a sweet tool to convert TeX directly to PDF. It can include bitmap graphics in the following formats: TIFF, JPEG, and PNG. He uses libtiff for including TIFF images.

He is using linux (redhat) i686, Checker-0.9.9.1 compiled with gcc-2.95.2.

Any ideas?

Tom

---------- Forwarded message ----------
Date: Fri, 10 Dec 1999 09:02:39 +0100 (MET)
From: Han The Thanh <thanh@informatics.muni.cz>
To: Tom Kacvinsky <tjk@ams.org>
Subject: libtiff problem

Hi Tom,

I found some problem in libtiff by a memmory checker, and sent a message to libtiff mailing list. But it didn't seem to arrive. I saw some your messages in the libtiff mailing list archive, so guess you know the developers. Here is the message I sent:

Dear libtiff developer(s),

I am using libtiff in an application for reading tiff images. When running the app with a memory checker, I got warnings (quite a lot) like:

-------------------------------------------------------------------------
...
>From Checker (pid:17179): (apd) access permission denied in mapped memory.
When Reading 168 byte(s) at address 0x4016a00a, inside the mmap zone.
Base: 0x40172000, 0x4016a000 length: 0x00002000, 0xa800306c
The region was mapped by:
        pc=0x08623991 in chkr_stub_mmap at /home/thanh/src/checker/stubs/stubs-sys_mman.c:47
        pc=0x08355292 in _tiffMapProc at /home/thanh/pdftex/src/libs/libtiff/tif_unix.c:81
        pc=0x0833737b in TIFFClientOpen at /home/thanh/pdftex/src/libs/libtiff/tif_open.c:347
        pc=0x0835562e in TIFFFdOpen at /home/thanh/pdftex/src/libs/libtiff/tif_unix.c:120
        pc=0x08355b63 in TIFFOpen at /home/thanh/pdftex/src/libs/libtiff/tif_unix.c:157

Stack frames are:
        pc=0x0862403e in chkr_stub_memcpy at /home/thanh/src/checker/stubs/stubs-string.c:96
        pc=0x08355fb0 in _TIFFmemcpy at /home/thanh/pdftex/src/libs/libtiff/tif_unix.c:187
        pc=0x082dd1fa in TIFFReadDirectory at /home/thanh/pdftex/src/libs/libtiff/tif_dirread.c:150
        pc=0x08337522 in TIFFClientOpen at /home/thanh/pdftex/src/libs/libtiff/tif_open.c:350
        pc=0x0835562e in TIFFFdOpen at /home/thanh/pdftex/src/libs/libtiff/tif_unix.c:120
        pc=0x08355b63 in TIFFOpen at /home/thanh/pdftex/src/libs/libtiff/tif_unix.c:157
...
-------------------------------------------------------------------------

It looks like some illegal memory access in libtiff, but I am not sure. I posted this message with hope it might be helpful for people who maintain and develop libtiff.

Regards,
Thanh