lug-bg: Fwd: Port of FreeBSD heap to Linux

[George Danchev <danchev@xxxxxxxxx>]

може да е интересно на някои sec изследователи.

----------  Forwarded Message  ----------

Subject: Port of FreeBSD heap to Linux
Date: Wednesday 28 January 2004 17:07
From: Georgi Guninski <guninski@xxxxxxxxxxxx>
To: security@xxxxxxxxxxxx

There is a port of the freebsd heap to linux at:
http://www.guninski.com/wares/free10.tar.gz
md5sum free10.tar.gz
c20d5f2d4790fdecc6d1f0005aaa9d2d  free10.tar.gz

The README:
--------------
Port of FreeBSD's heap implementation to Linux.

This is a linux port of the heap implementation originally written
by phk@xxxxxxxxxxx.

Why: It is considered safer than the linux heap implementation.
double free bugs does not seem exploitable, some heap overflows also may
not be exploitable.
Of course it *does not* give 100% protection against heap mischief.

Ported to linux by Georgi Guninski guninski@xxxxxxxxxxxx

INSTALL
1. make
2. cp mallib.so /usr/local/lib
3. LD_PRELOAD=/usr/local/lib/mallib.so PROGRAM
or export LD_PRELOAD=/usr/local/lib/mallib.so



mallib.so should be readable and executable by all users.

to check if the new heap is loaded:
cat /proc/<pid>/maps
mallib.so should be in the output.

to use the new heap globally:
put in /etc/ld.so.preload
/usr/local/lib/mallib.so


To change the heap options
# cd /etc
# ln -s <options> /etc/malloc.conf

The shared library works with static binaries also.

NOTE:
if you use it globally, start a program after editing /etc/ld.so.preload to
check whether it works before booting.
If there is a problem, you may need to remove mallib.so from ld.so.preload.

DON'T OVERWRITE mallib.so if it is running globally - box may freeze!

Globally works on debian and redhat.


KNOWN BUGS:

1.memalign() is just a wrapper to malloc() which is not correct.
2.does the mutex stuff work?
3.The only bug I have encountered is a X server and KDE crash on debian.
4.What are the best options for the bsd heap - /etc/malloc.conf

TODO:
1. Make memalign work as expected.

CREDITS
gbr, peio
for testing

--
georgi

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You may visit Guninski Security Mailing List page at
http://www.guninski.com/mailinglist.html
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