Bug 537636

Résumé:

SELinux is preventing /usr/bin/empathy from making the program stack executable.

Description détaillée:

The empathy 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 empathy 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.

Autoriser l'accès:

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 empathy to
run correctly, you can change the context of the executable to execmem_exec_t.
"chcon -t execmem_exec_t '/usr/bin/empathy'" 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/bin/empathy'"

Commande de correction:

chcon -t execmem_exec_t '/usr/bin/empathy'

Informations complémentaires:

Contexte source               unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1
                              023
Contexte cible                unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1
                              023
Objets du contexte            None [ process ]
source                        empathy
Chemin de la source           /usr/bin/empathy
Port                          <Inconnu>
Hôte                         (removed)
Paquetages RPM source         empathy-2.28.1.1-3.fc12
Paquetages RPM cible          
Politique RPM                 selinux-policy-3.6.32-41.fc12
Selinux activé               True
Type de politique             targeted
MLS activé                   True
Mode strict                   Enforcing
Nom du plugin                 allow_execstack
Nom de l'hôte                (removed)
Plateforme                    Linux (removed) 2.6.31.5-127.fc12.x86_64 #1
                              SMP Sat Nov 7 21:11:14 EST 2009 x86_64 x86_64
Compteur d'alertes            4
Première alerte              sam. 14 nov. 2009 20:44:18 CET
Dernière alerte              dim. 15 nov. 2009 11:37:47 CET
ID local                      fa7094eb-537a-49c4-b5d7-8751cbf0ddc0
Numéros des lignes           

Messages d'audit bruts        

node=(removed) type=AVC msg=audit(1258281467.984:21): avc:  denied  { execstack } for  pid=1968 comm="empathy" 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(1258281467.984:21): arch=c000003e syscall=10 success=no exit=-13 a0=7fff7f131000 a1=1000 a2=1000007 a3=3aa9619aeb items=0 ppid=1967 pid=1968 auid=500 uid=500 gid=500 euid=500 suid=500 fsuid=500 egid=500 sgid=500 fsgid=500 tty=(none) ses=1 comm="empathy" exe="/usr/bin/empathy" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)



Hash String generated from  selinux-policy-3.6.32-41.fc12,allow_execstack,empathy,unconfined_t,unconfined_t,process,execstack
audit2allow suggests:

#============= unconfined_t ==============
allow unconfined_t self:process execstack;