The following was filed automatically by setroubleshoot: Summary: SELinux is preventing /usr/bin/nautilus from making the program stack executable. Detailed Description: [SELinux is in permissive mode. This access was not denied.] The nautilus 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 nautilus 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 nautilus to run correctly, you can change the context of the executable to execmem_exec_t. "chcon -t execmem_exec_t '/usr/bin/nautilus'" 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/nautilus'" Fix Command: chcon -t execmem_exec_t '/usr/bin/nautilus' 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 nautilus Source Path /usr/bin/nautilus Port <Unknown> Host (removed) Source RPM Packages nautilus-2.27.92-2.fc12 Target RPM Packages Policy RPM selinux-policy-3.6.31-5.fc12 Selinux Enabled True Policy Type targeted MLS Enabled True Enforcing Mode Permissive Plugin Name allow_execstack Host Name (removed) Platform Linux (removed) 2.6.31-14.fc12.x86_64 #1 SMP Tue Sep 15 03:48:57 EDT 2009 x86_64 x86_64 Alert Count 2 First Seen Wed 16 Sep 2009 07:40:27 PM EDT Last Seen Wed 16 Sep 2009 07:40:27 PM EDT Local ID 3226dcfa-f9ee-4658-aed2-9b67ca60158d Line Numbers Raw Audit Messages node=(removed) type=AVC msg=audit(1253144427.289:379): avc: denied { execstack } for pid=2982 comm="nautilus" 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=AVC msg=audit(1253144427.289:379): avc: denied { execmem } for pid=2982 comm="nautilus" 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(1253144427.289:379): arch=c000003e syscall=10 success=yes exit=0 a0=7fff27b0c000 a1=1000 a2=1000007 a3=312b61aaf9 items=0 ppid=2874 pid=2982 auid=500 uid=500 gid=500 euid=500 suid=500 fsuid=500 egid=500 sgid=500 fsgid=500 tty=(none) ses=31 comm="nautilus" exe="/usr/bin/nautilus" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null) audit2allow suggests: #============= unconfined_t ============== allow unconfined_t self:process { execstack execmem };
Nautilus should not require execstack/execmem http://people.redhat.com/~drepper/selinux-mem.html Dawid, If this is actually causing things to blow up you can turn on the allow_execstack boolean. setsebool -P allow_execstack 1
Daniel, I've filled this bug via the ABRT in SETroubleshoot after I updated my rawhide install to latest policy and relabel on boot. I'm running SELinux in permissive mode so everything works well except I get the warnings sometimes. I know it's rawhide and things like that may happen often and I generally do not file BZ as it might be fixed in the next 'yum update'. I saw this particular alert since about a week so I thought it might be useful to BZ it.
Yes this is very useful. Ordinarily during Fedora 11 we ran with the allow_execstack boolean turned on, because of buggy apps, We are trying to make sure no apps in F12 that we ship require this priv, since it is somewhat dangerous.
Hmm. Dan, is there any way to get a stacktrace from when this happens ? Dawid, do you have any nautilus plugins installed ? Say, nautilus-open-terminal or nautilus-actions ?
I guess you could ask the reporter to run strace on nautilus and try to get it to repeat. He is probably seeing a mprot failure. Of course since he is in permissive mode there will be no error in strace.
Yes, I've got these installed: nautilus.x86_64 2.28.0-2.fc12 @rawhide nautilus-actions.x86_64 1.12.0-1.fc12 @rawhide nautilus-extensions.x86_64 2.28.0-2.fc12 @rawhide nautilus-open-terminal.x86_64 0.17-2.fc12 @rawhide nautilus-search-tool.x86_64 0.3.0-3.fc12 @rawhide nautilus-sendto.x86_64 2.28.0-1.fc12 @rawhide I also have seen this alert with epiphany (2.27.x - I did not get today's update yet) and chromium (it's not in fedora). Since I run in permissive mode, this is not a problem for me now but when final Fedora is released I'll switch to enforcing mode. I know that we Fedora does not support software that does not come from official repos (like the chromium) but I still would prefer to keep the SELinux boolean on. So now finally is my question: Is it feasible to enable exclusion of certain binaries from execmem,stack etc protections and yet keep the global flag on so that I can exclude eg chromium from the protection and keep the rest of the system protected?
PS. I'll run nautilus with strace as soon as I get back home from work :-)
Once you've figured out how to reproduce this and detect it in strace, you could remove the extensions one-by-one to see which one causes this.
Dawid, please note that not only nautilus-* packages provide extensions for nautilus, see the contents of /usr/lib64/nautilus/extensions-2.0 directory.
*** Bug 524446 has been marked as a duplicate of this bug. ***
It seems that this has somehow fixed itself as I'm not getting this alert anymore since about a week. Previously I was getting at least one such warning per day and now nothing.. I did not change any booleans and I did not remove any of nautilus-related packages - just daily yum update.
Ok I can go with a miracle. I will close for now and reopen if it happens again.