On Wed, 2009-05-20 at 22:57 +0800, Dennis Wronka wrote:
> Okay, here we go:
>
> I unmounted /selinux and then got this:
> load_policy: Can't load policy: Invalid argument
>
> I attached my kernel-config and the two traces (trace1 for the "Device or
> resource busy"-error, trace2 for the "Invalid argument"-error).
Possible patch for libselinux to a) gracefully handle the situation
where selinuxfs is already mounted, b) report errors when switching to
permissive, and c) proceed with the policy load even if we cannot switch
to permissive mode as requested, as proceeding without a policy when the
kernel only supports enforcing mode is not desirable.
Signed-off-by: Joshua Brindle <method@manicmethod.com>
Al was complaining that he has selinux disabled and has 100,000+ mounts
in /proc/mounts. Every time he runs ls the thing takes 5 seconds
because the libselinux constructor runs the entirety of his /proc/mounts
looking for selinuxfs, which doesn't exist. Speed things up by first
checking for selinuxfs in /proc/filesystems, only if the fs is even
registered should we bother to run all of /proc/mounts.
Signed-off-by: Eric Paris <eparis@redhat.com>
Email: tmraz@redhat.com
Subject: Problems with freeing thread local storage in libselinux
Date: Wed, 06 May 2009 12:38:35 +0200
On Wed, 2009-05-06 at 01:32 -0500, Manoj Srivastava wrote:
> Hi folks,
>
> There have been numerous reports in Debian and derivatives of
> programs linked with libselinux intermittently getting segfaults.
> There is, for instance, the Debian report 505920[0], and Ubuntu
> reports[1], [3] and [5], and Gnome [2]. I have not been able to
> reproduce the error myself, though I have run the test cases a number
> of times.
>
> The common thread in unclutter, libavg, gst-inspect et al. is a
> segmentation fault in libselinux1, in the 'fini' destructor functions,
> referencing the thread local variables.
>
> The Ubuntu bug log reference my old patch for libselinux from
> 1.X days, where I replaced the thread local storage with regular
> variables and mutexes, and people report success with that. I suspect
> that something is corrupting the thread local storage. From the ubuntu
> report:
> --8<---------------cut here---------------start------------->8---
> Valgrind reports:
> =29183== Invalid read of size 8
> ==29183== at 0xE29B9DD: fini_context_translations (setrans_client.c:211)
> ==29183== by 0xE28F1F1: (within /lib/libselinux.so.1)
> ==29183== by 0xE29D040: (within /lib/libselinux.so.1)
> ==29183== by 0x570010F: exit (exit.c:75)
> 505920==29183== by 0x56E91CA: (below main) (libc-start.c:252)
> ==29183== Address 0x80 is not stack'd, malloc'd or (recently) free'd
> ==29183==
> ==29183== Process terminating with default action of signal 11 (SIGSEGV): dumping core
> ==29183== Access not within mapped region at address 0x80
> ==29183== at 0xE29B9DD: fini_context_translations (setrans_client.c:211)
> ==29183== by 0xE28F1F1: (within /lib/libselinux.so.1)
> ==29183== by 0xE29D040: (within /lib/libselinux.so.1)==29183== by 0x570010F: exit (exit.c:75)
> ==29183== by 0x56E91CA: (below main) (libc-start.c:252)
>
>
> (gdb) bt
> #0 0x00007f3ae812a9dd in fini_context_translations () at setrans_client.c:211
> #1 0x00007f3ae811e1f2 in __do_global_dtors_aux () from /lib/libselinux.so.1
> #2 0x00007ffff9097700 in ?? ()
> #3 0x00007f3ae812c041 in _fini () from /lib/libselinux.so.1
> #4 0x00007ffff9097700 in ?? ()
> #5 0x00007f3af0e88796 in _dl_fini () from /lib64/ld-linux-x86-64.so.2
> Backtrace stopped: previous frame inner to this frame (corrupt stack?)
> --8<---------------cut here---------------end--------------->8---
>
> There have been two sets of patches proposed for this; first one
> merely initializes the variables in the init function, and this works
> for a number of people, but at least one person has reported a second
> segfault even with the patch installed[6]
>
> The second patch below converts a thread local cache to a
> process wide cache, with mutex guards, which makes the cache slower,
> and non-thread local caches means that cache misses are more likely.
>
> I'll try and follow up with people who can reproduce the
> problems to see if either one of the patches solve their problems
> without triggering other segmentation faults, but I'd appreciate
> comments if anyone has insight into the issue.
The problem is with freeing storage referenced by TLS variables in
destructors. The destructor is called only in one of the threads and the
variables might not be even properly initialized in that thread. One
possibility is to not free the storage at all but that will leak memory
if the libselinux is loaded/unloaded multiple times in a process.
The only proper way is to use TSD (pthread_key_create,
pthread_setspecific etc.) to store the pointers to the cached contexts.
The attached patch implements this. I did not test it thoroughly though.
--
Tomas Mraz
No matter how far down the wrong road you've gone, turn back.
Turkish proverb
Signed-off-by: Chad Sellers <csellers@tresys.com>
Email: dwalsh@redhat.com
Subject: SELinux context patch
Date: Mon, 18 May 2009 14:16:12 -0400
This patch adds context files for virtual_domain and virtual_image,
these are both being used to locat the default context to be executed by
svirt.
I also included the subs patch which I submitted before. This patch
allows us to substitute prefixes to matchpathcon.
So we can say /export/home == /home
and
/web == /var/www
Author: Chad Sellers
Email: csellers@tresys.com
Flipped free()'s in original patch when strdup'd fail to proper order.
Signed-off-by: Chad Sellers <csellers@tresys.com>
Email: dwalsh@redhat.com
Subject: Patch to getdefaultcon to print just the correct match and add verbose option
Date: Wed, 04 Mar 2009 15:41:37 -0500
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I really want to rename this to selinuxdefaultcon, which is what we ship
in Fedora.
Also exit with proper error on failure.
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Signed-off-by: Chad Sellers <csellers@tresys.com>
Email: dwalsh@redhat.com
Subject: We have moved matchpathcon to /sbin from /usr/sbin
Date: Wed, 01 Apr 2009 10:21:53 -0400
Some init scripts wanted to use matchpathcon before /usr is mounted.
Author: Chad Sellers
Email: csellers@tresys.com
Added matchpathcon to clean target
Signed-off-by: Chad Sellers <csellers@tresys.com>
Email: dwalsh@redhat.com
Subject: Patch matchpathcon to eliminate file "/"
Date: Wed, 04 Mar 2009 15:39:31 -0500
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So
matchpathcon /etc/
Will work the same as
matchpathcon /etc
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Signed-off-by: Chad Sellers <csellers@tresys.com>
interface something like: int security_deny_unknown(void);
This interface can suggest applications preferable behavior when
string_to_security_class() or string_to_av_perm() returns invalid
value which means the security policy does not define required
ones.
Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Since the v2.6.26 kernel, SELinux has supported an idea of permissive
domain which allows certain processes to work as if permissive mode,
even if the global setting is enforcing mode.
However, we don't have an application program interface to inform
what domains are permissive one, and what domains are not.
It means applications focuses on SELinux (XACE/SELinux, SE-PostgreSQL
and so on) cannot handle permissive domain correctly.
This patch add the sixth field (flags) on the reply of the /selinux/access
interface which is used to make an access control decision from userspace.
If the first bit of the flags field is positive, it means the required
access control decision is on permissive domain, so application should
allow any required actions, as the kernel doing.
This patch also has a side benefit. The av_decision.flags is set at
context_struct_compute_av(). It enables to check required permissions
without read_lock(&policy_rwlock).
Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
messages via netlink socket from SELinux.
* Two new callbacks were added to selinux_set_callback(3)
- SELINUX_CB_SETENFORCE
is invoked when it got SELNL_MSG_SETENFORCE message in the
avc_netlink_process().
- SELINUX_CB_POLICYLOAD
is invoked when it got SELNL_MSG_POLICYLOAD message in the
avc_netlink_process().
* Three functions were exposed to applications.
- int avc_netlink_open(int blocking);
- void avc_netlink_loop(void);
- void avc_netlink_close(void);
Due to a few reasons, SE-PostgreSQL implements its own userspace
avc, so it needs to copy and paste some of avc_internal.c.
This update enables to share common part from such kind of application.
Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
windows with selinux running. Part of the reason for this was because
libselinux called into the kernel /selinux/create interface for every
object. This patch caches the results of /selinux/create in the
userspace avc to significantly increase the speed of these types of
operations.
Revised to correct locking, interface issues.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Eamon Walsh <ewalsh@tycho.nsa.gov>
Email: dwalsh@redhat.com
Subject: Add restorecon and install methods for libselinux python bindings.
Date: Tue, 06 Jan 2009 10:31:04 -0500
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Daniel J Walsh wrote:
> Joshua Brindle wrote:
>> Daniel J Walsh wrote:
>> Luke Macken wrote restorecon and install functions used in Fedora
>> Infrastructure which can be used to install files with the proper
>> context and to fix the labels of files/directories without having to
>> exec restorecon.
>
>> diff --exclude-from=exclude -N -u -r
>> nsalibselinux/src/selinuxswig_python.i
>> libselinux-2.0.75/src/selinuxswig_python.i
>> --- nsalibselinux/src/selinuxswig_python.i 2008-08-28
>> 09:34:24.000000000 -0400
>> +++ libselinux-2.0.75/src/selinuxswig_python.i 2008-11-14
>> 17:09:50.000000000 -0500
>> @@ -6,6 +6,32 @@
>> #include "selinux/selinux.h"
>> %}
>
>> +%pythoncode %{
>> +
>> +import shutil, os
>> +
>> +def restorecon(path, recursive=False):
>> + """ Restore SELinux context on a given path """
>> + mode = os.stat(path)[stat.ST_MODE]
>
>> stat doesn't exist here, perhaps he meant mode?
>
>> + status, context = matchpathcon(path, mode)
>> + if status == 0:
>> + lsetfilecon(path, context)
>> + if recursive:
>> + os.path.walk(path, lambda arg, dirname, fnames:
>> + map(restorecon, [os.path.join(dirname, fname)
>> + s for fname in fnames]),
>> None)
>
>> typo, the s causes a syntax error
>
>> +
>> +def copytree(src, dest):
>> + """ An SELinux-friendly shutil.copytree method """
>> + shutil.copytree(src, dest)
>> + restorecon(dest, recursive=True)
>> +
>> +def install(src, dest):
>> + """ An SELinux-friendly shutil.move method """
>> + shutil.move(src, dest)
>> + restorecon(dest, recursive=True)
>> +%}
>> +
>> /* security_get_boolean_names() typemap */
>> %typemap(argout) (char ***names, int *len) {
>> PyObject* list = PyList_New(*$2);
>
>> This patch doesn't appear correct, I'll fix the things above, have you
>> been testing this at all?
>
> Must have sent you a bad patch.
>
>
> This is what the current patch looks like.
>
And this is still broken.
One more fix.
+ mode = os.stat(path)[stat.ST_MODE]
should be
+ mode = os.lstat(path)[stat.ST_MODE]
Modified to remove copytree and install functions
Signed-off-by: Joshua Brindle <method@manicmethod.com>
Currently, the message types are defined but not used.
This will allow better separation of messages when logging to facilities
such as libaudit.
Signed-off-by: Eamon Walsh <ewalsh@tycho.nsa.gov>
Email: dwalsh@redhat.com
Subject: matchpathcon -V does not always work as expected.
Date: Tue, 30 Sep 2008 08:54:18 -0400
matchpathcon -V should be passing the mode when checking whether the
file context on a file is correct.
Signed-off-by: Joshua Brindle <method@manicmethod.com>
Email: dwalsh@redhat.com
Subject: Some missing man pages from libselinux
Date: Wed, 24 Sep 2008 08:57:44 -0400
We are still missing the following man pages.
Perhaps some of these functions should be removed?
selinux_users_path seems to return a bogus directory?
Also do not have _raw functions defined in man pages.
matchpathcon_checkmatches
matchpathcon_filespec_add
matchpathcon_filespec_destroy
matchpathcon_filespec_eval
matchpathcon_index
matchpathcon_init_prefix
print_access_vector
security_canonicalize_context
security_disable
security_set_boolean_list
selinux_check_passwd_access
selinux_customizable_types_path
selinux_file_context_cmp
selinux_file_context_verify
selinux_get_callback
selinux_init_load_policy
selinux_lsetfilecon_default
selinux_mkload_policy
selinux_raw_to_trans_context
selinux_trans_to_raw_context
selinux_translations_path
selinux_users_path
set_selinuxmnt
Signed-off-by: Joshua Brindle <method@manicmethod.com>
