[patch] exec-shield-2.6.0-test6-G3

Gabor MICSKO
2003-09-28T14:57:43Z

Hi!

I`ve made a port of the Ingo's last exec-shield patch. This is my second
patch, so please test this one carefully.

Against vanilla 2.6.0-test6:
http://www.hup.hu/old/stuff/kernel/exec-shield/exec-shield-2.6.0-test6-G3

Comments, feedbacks welcome.

Test:

Kernel:
Linux sunshine 2.6.0-test6-exec-shield-nptl #1 SMP Sun Sep 28 14:49:15
CEST 2003 i686 GNU/Linux

Test programs:
http://www.research.avayalabs.com/project/libsafe/src/libsafe-2.0-16.tgz
http://pageexec.virtualave.net/paxtest-0.9.1.tar.gz

===========================================
sunshine:/home/trey/exec/libsafe-2.0-16/exploits# echo "2" >
/proc/sys/kernel/exec-shield
sunshine:/home/trey/exec/libsafe-2.0-16/exploits# cat
/proc/sys/kernel/exec-shield
2
===========================================

libsafe-2.0-16 (exec-shield full protection):

---------------------------------------------------------------------
sunshine:/home/trey/exec/libsafe-2.0-16/exploits# ./canary-exploit
This program tries to use printf("%n") to overwrite the
return address on the stack.
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
Segmentation fault
sunshine:/home/trey/exec/libsafe-2.0-16/exploits#
---------------------------------------------------------------------

---------------------------------------------------------------------
sunshine:/home/trey/exec/libsafe-2.0-16/exploits#
./exploit-non-exec-stack
This program demonstrates how a (stack) buffer overflow
can attack linux kernels with *non-executable* stacks.
This is variation on return-int-libc attack.
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
Segmentation fault
sunshine:/home/trey/exec/libsafe-2.0-16/exploits#
---------------------------------------------------------------------

---------------------------------------------------------------------
trey@sunshine:~/exec/libsafe-2.0-16/exploits$ ./t1
This program tries to use strcpy() to overflow the buffer.
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
Segmentation fault
trey@sunshine:~/exec/libsafe-2.0-16/exploits$
---------------------------------------------------------------------

---------------------------------------------------------------------
trey@sunshine:~/exec/libsafe-2.0-16/exploits$ ./t1w
This program tries to use strcpy() to overflow the buffer.
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
Segmentation fault
trey@sunshine:~/exec/libsafe-2.0-16/exploits$
---------------------------------------------------------------------

---------------------------------------------------------------------
trey@sunshine:~/exec/libsafe-2.0-16/exploits$ ./t3
This program will exec() a new program. The new program will
overflow the buffer using strcpy().
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
Segmentation fault
trey@sunshine:~/exec/libsafe-2.0-16/exploits$
---------------------------------------------------------------------

---------------------------------------------------------------------
trey@sunshine:~/exec/libsafe-2.0-16/exploits$ ./t3w
This program will exec() a new program. The new program will
overflow the buffer using strcpy().
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
Segmentation fault
trey@sunshine:~/exec/libsafe-2.0-16/exploits$
---------------------------------------------------------------------

---------------------------------------------------------------------
trey@sunshine:~/exec/libsafe-2.0-16/exploits$ ./t4
This program will fork() child process, and the child
will overflow the buffer using strcpy().
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
parent process terminating
trey@sunshine:~/exec/libsafe-2.0-16/exploits$
---------------------------------------------------------------------

---------------------------------------------------------------------
trey@sunshine:~/exec/libsafe-2.0-16/exploits$ ./t4w
This program will fork() child process, and the child
will overflow the buffer using strcpy().
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
parent process terminating
trey@sunshine:~/exec/libsafe-2.0-16/exploits$
---------------------------------------------------------------------

---------------------------------------------------------------------
trey@sunshine:~/exec/libsafe-2.0-16/exploits$ ./t5
This program tries to use strcat() to overflow the buffer.
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
Segmentation fault
trey@sunshine:~/exec/libsafe-2.0-16/exploits$
---------------------------------------------------------------------

---------------------------------------------------------------------
trey@sunshine:~/exec/libsafe-2.0-16/exploits$ ./t6
This program tries to use scanf() to overflow the buffer.
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
Segmentation fault
trey@sunshine:~/exec/libsafe-2.0-16/exploits$
---------------------------------------------------------------------

===========================================
sunshine:/home/trey/exec/libsafe-2.0-16/exploits# echo "0" >
/proc/sys/kernel/exec-shield
sunshine:/home/trey/exec/libsafe-2.0-16/exploits# cat
/proc/sys/kernel/exec-shield
0
===========================================

libsafe-2.0-16 (exec-shield off):

---------------------------------------------------------------------
trey@sunshine:~/exec/libsafe-2.0-16/exploits$ ./canary-exploit
This program tries to use printf("%n") to overwrite the
return address on the stack.
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
sh-2.05b$ exit
exit
trey@sunshine:~/exec/libsafe-2.0-16/exploits$
---------------------------------------------------------------------

---------------------------------------------------------------------
trey@sunshine:~/exec/libsafe-2.0-16/exploits$ ./exploit-non-exec-stack
This program demonstrates how a (stack) buffer overflow
can attack linux kernels with *non-executable* stacks.
This is variation on return-int-libc attack.
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
sh-2.05b$ exit
exit
trey@sunshine:~/exec/libsafe-2.0-16/exploits$
---------------------------------------------------------------------

---------------------------------------------------------------------
trey@sunshine:~/exec/libsafe-2.0-16/exploits$ ./t1
This program tries to use strcpy() to overflow the buffer.
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
sh-2.05b$ exit
exit
trey@sunshine:~/exec/libsafe-2.0-16/exploits$
---------------------------------------------------------------------

---------------------------------------------------------------------
trey@sunshine:~/exec/libsafe-2.0-16/exploits$ ./t1w
This program tries to use strcpy() to overflow the buffer.
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
sh-2.05b$ exit
exit
trey@sunshine:~/exec/libsafe-2.0-16/exploits$
---------------------------------------------------------------------

---------------------------------------------------------------------
trey@sunshine:~/exec/libsafe-2.0-16/exploits$ ./t3
This program will exec() a new program. The new program will
overflow the buffer using strcpy().
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
sh-2.05b$ exit
exit
trey@sunshine:~/exec/libsafe-2.0-16/exploits$
---------------------------------------------------------------------

---------------------------------------------------------------------
trey@sunshine:~/exec/libsafe-2.0-16/exploits$ ./t3w
This program will exec() a new program. The new program will
overflow the buffer using strcpy().
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
sh-2.05b$ exit
exit
trey@sunshine:~/exec/libsafe-2.0-16/exploits$
---------------------------------------------------------------------

---------------------------------------------------------------------
trey@sunshine:~/exec/libsafe-2.0-16/exploits$ ./t4
This program will fork() child process, and the child
will overflow the buffer using strcpy().
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
sh-2.05b$ exit
exit
parent process terminating
trey@sunshine:~/exec/libsafe-2.0-16/exploits$
---------------------------------------------------------------------

---------------------------------------------------------------------
trey@sunshine:~/exec/libsafe-2.0-16/exploits$ ./t5
This program tries to use strcat() to overflow the buffer.
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
sh-2.05b$ exit
exit
trey@sunshine:~/exec/libsafe-2.0-16/exploits$
---------------------------------------------------------------------

---------------------------------------------------------------------
trey@sunshine:~/exec/libsafe-2.0-16/exploits$ ./t6
This program tries to use scanf() to overflow the buffer.
If you get a /bin/sh prompt, then the exploit has worked.
Press any key to continue...
sh-2.05b$ exit
exit
trey@sunshine:~/exec/libsafe-2.0-16/exploits$
---------------------------------------------------------------------

*********************************************************************

===========================================
sunshine:/home/trey/exec/paxtest-0.9.1# echo "2" >
/proc/sys/kernel/exec-shield
sunshine:/home/trey/exec/paxtest-0.9.1# cat /proc/sys/kernel/exec-shield
2
===========================================

paxtest-0.9.1 (exec-shield full protection):

sunshine:/home/trey/exec/paxtest-0.9.1# ./paxtest
It may take a while for the tests to complete
Test results:
Executable anonymous mapping : Killed
Executable bss : Killed
Executable data : Killed
Executable heap : Killed
Executable stack : Killed
Executable anonymous mapping (mprotect) : Killed
Executable bss (mprotect) : Vulnerable
Executable data (mprotect) : Vulnerable
Executable heap (mprotect) : Vulnerable
Executable shared library bss (mprotect) : Vulnerable
Executable shared library data (mprotect): Vulnerable
Executable stack (mprotect) : Vulnerable
Anonymous mapping randomisation test : 8 bits (guessed)
Heap randomisation test (ET_EXEC) : 13 bits (guessed)
Heap randomisation test (ET_DYN) : 13 bits (guessed)
Main executable randomisation (ET_EXEC) : No randomisation
Main executable randomisation (ET_DYN) : 12 bits (guessed)
Shared library randomisation test : 12 bits (guessed)
Stack randomisation test (SEGMEXEC) : 17 bits (guessed)
Stack randomisation test (PAGEEXEC) : 17 bits (guessed)
Return to function (strcpy) : Vulnerable
Return to function (memcpy) : Vulnerable
Executable shared library bss : Killed
Executable shared library data : Killed
Writable text segments : Vulnerable

===========================================
sunshine:/home/trey/exec/paxtest-0.9.1# echo "0" >
/proc/sys/kernel/exec-shield
sunshine:/home/trey/exec/paxtest-0.9.1# cat /proc/sys/kernel/exec-shield
0
===========================================

paxtest-0.9.1 (exec-shield off):

sunshine:/home/trey/exec/paxtest-0.9.1# ./paxtest
It may take a while for the tests to complete
Test results:
Executable anonymous mapping : Vulnerable
Executable bss : Vulnerable
Executable data : Vulnerable
Executable heap : Vulnerable
Executable stack : Vulnerable
Executable anonymous mapping (mprotect) : Vulnerable
Executable bss (mprotect) : Vulnerable
Executable data (mprotect) : Vulnerable
Executable heap (mprotect) : Vulnerable
Executable shared library bss (mprotect) : Vulnerable
Executable shared library data (mprotect): Vulnerable
Executable stack (mprotect) : Vulnerable
Anonymous mapping randomisation test : No randomisation
Heap randomisation test (ET_EXEC) : No randomisation
Heap randomisation test (ET_DYN) : No randomisation
Main executable randomisation (ET_EXEC) : No randomisation
Main executable randomisation (ET_DYN) : No randomisation
Shared library randomisation test : No randomisation
Stack randomisation test (SEGMEXEC) : No randomisation
Stack randomisation test (PAGEEXEC) : No randomisation
Return to function (strcpy) : Vulnerable
Return to function (memcpy) : Vulnerable
Executable shared library bss : Vulnerable
Executable shared library data : Vulnerable
Writable text segments : Vulnerable

-----------------------------------------
#EOF

--
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-----------------------------------
Micskó Gábor
Compaq Accredited Platform Specialist, System Engineer (APS, ASE)
Szintézis Computer Rendszerház Rt.
H-9021 Győr, Tihanyi Árpád út 2.
Tel: +36-96-502-216
Fax: +36-96-318-658
E-mail: gmicsko@szintezis.hu
Web: http://www.hup.hu/