Bug 628031

Summary:

SELinux is preventing /usr/lib64/firefox-3.6/firefox from making the program
stack executable.

Detailed Description:

The firefox application attempted to make its stack executable. This is a
potential security problem. This should never ever be necessary. Stack memory is
not executable on most OSes these days and this will not change. Executable
stack memory is one of the biggest security problems. An execstack error might
in fact be most likely raised by malicious code. Applications 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. If firefox does not work and you need it to work,
you can configure SELinux temporarily to allow this access until the application
is fixed. Please file a bug report.

Allowing Access:

Sometimes a library is accidentally marked with the execstack flag, if you find
a library with this flag you can clear it with the execstack -c LIBRARY_PATH.
Then retry your application. If the app continues to not work, you can turn the
flag back on with execstack -s LIBRARY_PATH. Otherwise, if you trust firefox to
run correctly, you can change the context of the executable to execmem_exec_t.
"chcon -t execmem_exec_t '/usr/lib64/firefox-3.6/firefox'" 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 execmem_exec_t
'/usr/lib64/firefox-3.6/firefox'"

Fix Command:

chcon -t execmem_exec_t '/usr/lib64/firefox-3.6/firefox'

Additional Information:

Source Context                unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1
                              023
Target Context                unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1
                              023
Target Objects                None [ process ]
Source                        firefox-bin
Source Path                   /home/joel/firefox/firefox-bin
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           firefox-3.6.4-2.fc14
Target RPM Packages           
Policy RPM                    selinux-policy-3.8.8-20.fc14
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Plugin Name                   allow_execstack
Host Name                     (removed)
Platform                      Linux (removed) 2.6.35.2-9.fc14.x86_64 #1 SMP Tue Aug
                              17 22:36:15 UTC 2010 x86_64 x86_64
Alert Count                   10
First Seen                    Fri 27 Aug 2010 01:12:46 PM EDT
Last Seen                     Fri 27 Aug 2010 01:20:15 PM EDT
Local ID                      7a7a6e69-edbe-471f-aa7c-c7e15a96e3d8
Line Numbers                  

Raw Audit Messages            

node=(removed) type=AVC msg=audit(1282929615.824:825): avc:  denied  { execstack } for  pid=8343 comm="firefox" scontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tcontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tclass=process

node=(removed) type=SYSCALL msg=audit(1282929615.824:825): arch=c000003e syscall=10 success=no exit=-13 a0=7ffffac62000 a1=1000 a2=1000007 a3=3b7a420000 items=0 ppid=8330 pid=8343 auid=500 uid=500 gid=500 euid=500 suid=500 fsuid=500 egid=500 sgid=500 fsgid=500 tty=pts4 ses=1 comm="firefox" exe="/usr/lib64/firefox-3.6/firefox" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)



Hash String generated from  allow_execstack,firefox-bin,unconfined_t,unconfined_t,process,execstack
audit2allow suggests:

#============= unconfined_t ==============
#!!!! This avc can be allowed using the boolean 'allow_execstack'

allow unconfined_t self:process execstack;