From mboxrd@z Thu Jan  1 00:00:00 1970
Subject: debugging confined domain with gdb
From: Eric Paris <eparis@redhat.com>
To: selinux@tycho.nsa.gov
Cc: dwalsh@redhat.com, sds@tycho.nsa.gov, cpebenito@tresys.com
Content-Type: text/plain
Date: Wed, 10 Oct 2007 15:28:13 -0400
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Mime-Version: 1.0
Sender: owner-selinux@tycho.nsa.gov
List-Id: selinux@tycho.nsa.gov

So I've hit on this, and now I've run into 2 other people who had
problems using the targeted policy when they attempt to use gdb to trace
a running process in a confined domain.

The example today was:
gdb /sbin/audispd $(pidof audispd)

type=SYSCALL msg=audit(1192471243.328:5985): arch=c000003e syscall=61 success=no exit=-13 a0=4bf6 a1=7fff23dfb32c 
a2=ffffffff80000000 a3=0 items=0 ppid=11732 pid=11792 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 
fsgid=0 tty=pts0 comm="gdb" exe="/usr/bin/gdb" subj=root:system_r:unconfined_t:s0-s0:c0.c1023 key=(null)

type=AVC msg=audit(1192471243.328:5985): avc:  denied  { signal } for  pid=11792 comm="gdb" 
scontext=root:system_r:auditd_t:s0 tcontext=root:system_r:unconfined_t:s0-s0:c0.c1023 tclass=process

Basically audispd now needs to be able to signal back to the unconfined
gdb process.

So, policy gurus, I want gdb to work out of the box.  I also don't want
to generically give everything in the world signal to unconfined_t
permissions.  What options do I have in policy, run gdb in an unconfined
domain and give every single other domain signal permission to it?  Is
there an easy way to do that without thousands upon thousands of new
rules?

I probably can do something horrible in the kernel like if my signal is
denied then go back and check "if A can ptrace B then B can signal A"
but this probably wouldn't go over well in some environments *evil grin*

So how do I make gdb and friends work out of the box?  Developers having
to turn off selinux (ok, so i just load a policy module) to debug their
work just isn't working and more....

-Eric


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