SELinux prevents Bricscad

[twohot]

The absence of a strong AutoCAD alternative (native to linux) had been a source of concern for me. I had waitied so long for a good CAD software for Linux and its here ... Bricscad v10. http://www.bricsys.com/en_INTL/ What a relief for Linux Architects & Engineers!

Now there is a new problem. SELinux won't allow it in Fedora and Bricsys supports only Red Hat & Ubuntu. I'm stuck again. Any idea how to make SELinux more merciful in my case? Meanwhile, their TGZ version works quite well (... but It'll be nice to run things normally)

Here is the SELinux Alert:

Summary:

SELinux is preventing /opt/bricsys/bricscad/v10/bricscad from loading
/opt/bricsys/bricscad/v10/libBrxGeo.so which requires text relocation.

Detailed Description:

The bricscad application attempted to load
/opt/bricsys/bricscad/v10/libBrxGeo.so which requires text relocation. This is a
potential security problem. Most libraries do not need this permission.
Libraries are sometimes coded incorrectly and request this permission. The
SELinux Memory Protection Tests
(http://people.redhat.com/drepper/selinux-mem.html) web page explains how to
remove this requirement. You can configure SELinux temporarily to allow
/opt/bricsys/bricscad/v10/libBrxGeo.so to use relocation as a workaround, until
the library is fixed. Please file a bug report.

Allowing Access:

If you trust /opt/bricsys/bricscad/v10/libBrxGeo.so to run correctly, you can
change the file context to textrel_shlib_t. "chcon -t textrel_shlib_t
'/opt/bricsys/bricscad/v10/libBrxGeo.so'" You must also change the default file
context files on the system in order to preserve them even on a full relabel.
"semanage fcontext -a -t textrel_shlib_t
'/opt/bricsys/bricscad/v10/libBrxGeo.so'"

Fix Command:

chcon -t textrel_shlib_t '/opt/bricsys/bricscad/v10/libBrxGeo.so'

Additional Information:

Source Context                unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1
                              023
Target Context                system_u:object_r:lib_t:s0
Target Objects                /opt/bricsys/bricscad/v10/libBrxGeo.so [ file ]
Source                        bricscad
Source Path                   /opt/bricsys/bricscad/v10/bricscad
Port                          <Unknown>
Host                          ambassador
Source RPM Packages           bricscadv10-10.4.4-1
Target RPM Packages           bricscadv10-10.4.4-1
Policy RPM                    selinux-policy-3.6.32-89.fc12
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Plugin Name                   allow_execmod
Host Name                     ambassador
Platform                      Linux ambassador 2.6.31.12-174.2.3.fc12.i686 #1
                              SMP Mon Jan 18 20:22:46 UTC 2010 i686 i686
Alert Count                   1
First Seen                    Sat 15 May 2010 02:54:40 AM WAT
Last Seen                     Sat 15 May 2010 02:54:40 AM WAT
Local ID                      cf5eba89-da53-4db7-b0a4-726d3282b67e
Line Numbers                  

Raw Audit Messages            

node=ambassador type=AVC msg=audit(1273888480.734:26): avc:  denied  { execmod } for  pid=2522 comm="bricscad" path="/opt/bricsys/bricscad/v10/libBrxGeo.so" dev=sdb3 ino=284435 scontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tcontext=system_u:object_r:lib_t:s0 tclass=file

node=ambassador type=SYSCALL msg=audit(1273888480.734:26): arch=40000003 syscall=125 success=no exit=-13 a0=22c5000 a1=215000 a2=5 a3=bff9d500 items=0 ppid=2512 pid=2522 auid=500 uid=500 gid=500 euid=500 suid=500 fsuid=500 egid=500 sgid=500 fsgid=500 tty=pts1 ses=1 comm="bricscad" exe="/opt/bricsys/bricscad/v10/bricscad" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)

[wmorri]

Hi,

I am going to assume that you followed the directions and tried the command that it gave you.

Fix Command:

chcon -t textrel_shlib_t '/opt/bricsys/bricscad/v10/libBrxGeo.so'

If you haven't tried that then I would start there.

[twohot]

Thanks wmorri:

You assumed correctly. LibBrxGeo.so was not the first file to get an AVC alert. It was the third ... The first two were just the same. Hence, SELinux is going to repeat that suggestion for a lot more than LibBrxGeo.so in that directory. I'm not used to the internal functioning of SELinux, so I don't know a faster/accurate way to a permanent solution and it seems a change of context, in this manner, will not survive a reboot ( ... again I may be wrong)

[wmorri]

I am not an expert when it comes to SELinux myself. I just wanted to make sure that you had tried that first.

[jpollard]

Originally Posted by twohot

Thanks wmorri:

You assumed correctly. LibBrxGeo.so was not the first file to get an AVC alert. It was the third ... The first two were just the same. Hence, SELinux is going to repeat that suggestion for a lot more than LibBrxGeo.so in that directory. I'm not used to the internal functioning of SELinux, so I don't know a faster/accurate way to a permanent solution and it seems a change of context, in this manner, will not survive a reboot ( ... again I may be wrong)

It will survive a reboot, but not a forced relabel.

And no, I don't know which one (or where) that is (yet).

[twohot]

Originally Posted by jpollard

It will survive a reboot, but not a forced relabel.

And no, I don't know which one (or where) that is (yet).

Reading up on SELinux (very geeky stuff ... not the kind of thing I'll decipher in one sitting). http://www.redhat.com/docs/manuals/e...pter-0013.html

I didn't get the last line, jpollard ... I mean the "which"

[jpollard]

Sorry - I ment which file to add the rule to. I don't know where the file is either.

It may be possible to set the rules using the "setsexxxx" utilities though, but again
I'm not sure since the only mods to the SELinux policy I've set were to enable samba
home directories.