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;
This started happening after installing the Sun/Oracle Java plugin for Firefox. Also, the referenced website for how to "remove the requirement" points to a useless page (http://people.redhat.com/drepper/selinux-mem.html).
I will fix the troubleshoot to point at http://www.akkadia.org/drepper/selinux-mem.html I do not know why oracles java plugin is forcing firefox to need execstack. I guess it is moving the java code internal versus executing java as a separate app, like the Fedora one does. I guess if you want to use their plugin you need to turn off the execstack check for unconfined users. # setsebool -P allow_execstack 1
Can you provide a narrower boolean, like "allow_browser_execstack"? Or, what would the best local policy module rules be? I would like to handle Sun Java without completely enabling execstack. - Mike
Does # chcon -t execmem_exec_t /usr/lib64/firefox-3.6/firefox Fix the problem?
Yes, it does. Thanks! - Mike