postfix, procmail and SELinux - No Go

[Paul Howarth]

Marc Schwartz (via MN) wrote:
> On Tue, 2006-07-18 at 14:11 +0100, Paul Howarth wrote:
> # Run restorecon to restore the SELinux context after re-building
> 10 01 * * * root /sbin/restorecon -rv /var/dcc
> 11 01 * * * root /sbin/restorecon -v /usr/local/bin/dccproc
> 
> 
>> I could add this to the dcc policy (or a separate local module for 
>> restorecon):
>> cron_system_entry(restorecon_t)
>>
>> However, I think that the "right" way to fix this would be to use 
>> restorecond and add an entry to /etc/selinux/restorecond.conf (the 
>> manpage for restorecond suggests 
>> /etc/selinux/POLICYTYPE/restorconfiles.conf but that file doesn't seem 
>> to exist, and the restorecond binary includes the string 
>> /etc/selinux/restorecond.conf).
>>
>> Maybe Dan could comment on that?

Try this instead of your cron jobs and see what happens:

# chkconfig --add restorecond
# chkconfig restorecond on

Edit /etc/selinux/restorecond.conf and add a line:

/usr/local/bin/dccproc

(is the restorecon of /var/dcc actually needed?)

If you have network-mounted home directories, you may want to remove the 
lines starting with "~"

Then:
# service restorecond start

>>> type=AVC msg=audit(1153053408.030:4599): avc:  denied  { execmod } for  pid=6019 comm="ld-linux.so.2" name="libGLcore.so.1.0.8762" d ev=hdc7 ino=3116816 scontext=user_u:system_r:prelink_t:s0 tcontext=root:object_r:lib_t:s0 tclass=file
>>> type=SYSCALL msg=audit(1153053408.030:4599): arch=40000003 syscall=125 success=no exit=-13 a0=5c8000 a1=78e000 a2=5 a3=bf84c100 item s=0 pid=6019 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) comm="ld-linux.so.2" exe="/lib/ld-2.4.so" sub j=user_u:system_r:prelink_t:s0
>>> type=AVC_PATH msg=audit(1153053408.030:4599):  path="/usr/lib/libGLcore.so.1.0.8762"
>>> type=AVC msg=audit(1153053408.034:4600): avc:  denied  { execmod } for  pid=6022 comm="ld-linux.so.2" name="libnvidia-tls.so.1.0.876 2" dev=hdc7 ino=3117829 scontext=user_u:system_r:prelink_t:s0 tcontext=root:object_r:lib_t:s0 tclass=file
>>> type=SYSCALL msg=audit(1153053408.034:4600): arch=40000003 syscall=125 success=no exit=-13 a0=a3e000 a1=1000 a2=5 a3=bfc98d40 items= 0 pid=6022 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) comm="ld-linux.so.2" exe="/lib/ld-2.4.so" subj= user_u:system_r:prelink_t:s0
>>> type=AVC_PATH msg=audit(1153053408.034:4600):  path="/usr/lib/tls/libnvidia-tls.so.1.0.8762"
>> Do you have nvidia video drivers installed using the nvidia installer 
>> rather than an RPM package? If so, you should probably see:
>> http://www.city-fan.org/tips/ProprietaryVideoDriverWarning
> 
> Yep.  I have never had a problem with them (dating back to RH 8.0, all
> on Dell laptops) and this is the first time that I had noted any avc's
> related to them.
> 
> I have a script that I ran when I first moved to FC5 to set the
> following:
> 
> /usr/sbin/setsebool -P allow_execstack=1
> /usr/sbin/setsebool -P allow_execmod=1
> 
> based upon documents that I had found elsewhere.

That's somewhat overkill and I wouldn't want to do that.

Undo it with:
# setsebool -P allow_execstack 0
# setsebool -P allow_execmod 0

Then fix the file contexts instead:

# semanage fcontext -a -f -- -t textrel_shlib_t 
'/usr/lib/libGL(core)?\.so(\.[^/]*)*'
# semanage fcontext -a -f -- -t textrel_shlib_t
'/usr/lib/libnvidia.*\.so(\.[^/]*)*'
# restorecon -v /usr/lib/libGL* /usr/lib/libnvidia*

Please check that these files have context type textrel_shlib_t after 
doing this.

The upstream policy has file contexts set for this but I fear they're 
falling foul of the file contexts ordering rules.

>>> type=PATH msg=audit(1153138559.711:8): item=0 name="/var/run/utmp" inode=87750 dev=fd:01 mode=0100664 ouid=0 ogid=22 rdev=00:00 obj= system_u:object_r:init_var_run_t:s0
>>> type=AVC msg=audit(1153138559.715:9): avc:  denied  { read } for  pid=2374 comm="mingetty" name="utmp" dev=dm-1 ino=87750 scontext=s ystem_u:system_r:getty_t:s0 tcontext=system_u:object_r:init_var_run_t:s0 tclass=file
>>> type=SYSCALL msg=audit(1153138559.715:9): arch=40000003 syscall=5 success=no exit=-13 a0=48909fd4 a1=0 a2=804a000 a3=48909fda items= 1 pid=2374 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) comm="mingetty" exe="/sbin/mingetty" s ubj=system_u:system_r:getty_t:s0
>>> type=CWD msg=audit(1153138559.715:9):  cwd="/"
>>> type=PATH msg=audit(1153138559.715:9): item=0 name="/var/run/utmp" inode=87750 dev=fd:01 mode=0100664 ouid=0 ogid=22 rdev=00:00 obj= system_u:object_r:init_var_run_t:s0
>>> type=AVC msg=audit(1153138559.715:10): avc:  denied  { read write } for  pid=2374 comm="mingetty" name="utmp" dev=dm-1 ino=87750 sco ntext=system_u:system_r:getty_t:s0 tcontext=system_u:object_r:init_var_run_t:s0 tclass=file
>>> type=SYSCALL msg=audit(1153138559.715:10): arch=40000003 syscall=5 success=no exit=-13 a0=48909fd4 a1=2 a2=0 a3=48909fda items=1 pid =2374 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) comm="mingetty" exe="/sbin/mingetty" subj=s ystem_u:system_r:getty_t:s0
>>> type=CWD msg=audit(1153138559.715:10):  cwd="/"
>> Your /var/run/utmp appears to be labelled init_var_run_t rather than 
>> initrc_var_run_t.
> 
> Yep:
> 
> # ls -lZ /var/run/utmp
> -rw-rw-r--  root utmp system_u:object_r:init_var_run_t /var/run/utmp
> 
> # restorecon /var/run/utmp
> 
> # ls -lZ /var/run/utmp
> -rw-rw-r--  root utmp system_u:object_r:initrc_var_run_t /var/run/utmp

Running restorecond should stop this happening again.

Paul.