This patch is based on comments from previous a patch to
remove the many uses of kernel_dgram_send() and incorporate
it into logging_send_syslog_msg().
v2 - enclose in ifdef for redhat
v3 - rebase this patch on e41def136a
Signed-off-by: Dave Sugar <dsugar@tresys.com>
Those mmap() calls are non-essential, though. They're issued by
fdopen(), which can also fall back to read().
Since there are few reasons to grant read access to audit logs other
than for using ausearch, I've added the dontaudits directly to the
relevant read interfaces.
This is a minor update of the last attempt at this patch.
Changes in .fc to label /etc/rsyslog.d(/.*)? as syslog_conf_t so all rsyslog config files are labeled syslog_conf_t (not just /etc/r?syslog.conf). Update .te file to allow rsyslog to read the directory now labeled syslog_conf_t (files of this type were already readable). Final (and new) change is in logging_admin_syslog interface so files_etc_filetrans now includes the optional filename so /etc/r?syslog.conf would be labeled correctly when created in etc_t.
The overall goal of this patch is that a domain using the logging_admin_syslog is able to create/edit files in /etc/rsyslog.d and they get created as syslog_conf_t AND other files created in /etc (or other etc_t labeled directory) don't get created with the syslog_conf_t type as they are not necessarily syslog configuration files.
Dave Sugar
dsugar@tresys.com
Signed-off-by: Dave Sugar <dsugar@tresys.com>
When auditctl logs a message to syslog, it needs to read /etc/localtime.
This is currently denied:
avc: denied { read } for pid=191 comm="auditctl" name="UTC"
dev="vda1" ino=394043 scontext=system_u:system_r:auditctl_t
tcontext=system_u:object_r:locale_t tclass=file permissive=1
avc: denied { open } for pid=191 comm="auditctl"
path="/usr/share/zoneinfo/UTC" dev="vda1" ino=394043
scontext=system_u:system_r:auditctl_t
tcontext=system_u:object_r:locale_t tclass=file permissive=1
This occurs for example at boot time when "/usr/bin/augenrules --load"
is run [1]. Here is an extract of "strace -s 256 -f /usr/bin/augenrules
--load":
[pid 635] execve("/sbin/auditctl", ["/sbin/auditctl", "-R",
"/etc/audit/audit.rules"], 0x1e77d80 /* 16 vars */) = 0
...
[pid 635] open("/etc/audit/audit.rules", O_RDONLY) = -1 ENOENT (No
such file or directory)
[pid 635] open("/etc/localtime", O_RDONLY|O_CLOEXEC) = 4
[pid 635] fstat(4, {st_mode=S_IFREG|0644, st_size=127, ...}) = 0
[pid 635] fstat(4, {st_mode=S_IFREG|0644, st_size=127, ...}) = 0
[pid 635] read(4, "TZif2\0\0\0\0\0\0\0\0\0\0\0"..., 4096) = 127
[pid 635] lseek(4, -71, SEEK_CUR) = 56
[pid 635] read(4, "TZif2\0\0\0\0\0\0\0\0\0\0\0", 4096) = 71
[pid 635] close(4) = 0
[pid 635] socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0) = 4
[pid 635] connect(4, {sa_family=AF_UNIX, sun_path="/dev/log"}, 110) = 0
[pid 635] sendto(4, "<14>Aug 12 08:59:53 auditctl: file
/etc/audit/audit.rules doesn't exist, skipping", 81, MSG_NOSIGNAL,
NULL, 0) = 81
[pid 635] exit_group(0) = ?
More precisely, auditctl uses vsyslog() from glibc, which uses
localtime_r() to fetch the time is in local timezone.
[1] On a systemd system, this command is automatically run by
auditd.service unit, cf.
https://github.com/linux-audit/audit-userspace/blob/v2.7.7/init.d/auditd.service#L21
Kernel commit 6941857e82ae ("selinux: add a map permission check
for mmap") added a map permission check on mmap so that we can
distinguish memory mapped access (since it has different implications
for revocation). The purpose of a separate map permission check on
mmap(2) is to permit policy to prohibit memory mapping of specific files
for which we need to ensure that every access is revalidated, particularly
useful for scenarios where we expect the file to be relabeled at runtime
in order to reflect state changes (e.g. cross-domain solution, assured
pipeline without data copying). The kernel commit is anticipated to
be included in Linux 4.13.
This refpolicy change defines map permission for refpolicy. It mirrors
the definition in the kernel classmap by adding it to the common
definitions for files and sockets. This will break compatibility for
kernels that predate the dynamic class/perm mapping support (< 2.6.33,
< RHEL 6); on such kernels, one would instead need to add map permission
to the end of each file and socket access vector.
This change only allows map permission as needed, e.g. only in the
mmap_file_perms and exec_file_perms object permission sets
(since map is always required there) and only in specific interfaces
or modules where denials were observed in limited testing.
It is important to note that effective use of this permission requires
complete removal of unconfined, as otherwise unconfined domains will be
able to map all file types and therefore bypass the intended protection.
If we wanted to exclude map permission to all file types by default from
unconfined, we would need to add it to the list of permissions excluded from
files_unconfined_type in kernel/files.te.
Policies that depend on this permission not being allowed to specific file
types should also make use of neverallow rules to ensure that this is not
undermined by any allow rule, and ensure that they are performing neverallow
checking at policy build time (e.g. make validate) or runtime (e.g.
semanage.conf expand-check=1).
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
This patch lets mandb_t search init_var_run_t dirs which it needs when running
with systems. Also allows it to fs_getattr_xattr_fs() because it seemed
pointless to put that in a separate patch.
Allow init_t to do several things that it requires when init is systemd.
Allow various operations on var_log_t to access var_log_t symlinks too.
Let auditd setattr it's directory.
I believe that I have addressed all the issues Chris raised, so here's a newer
version of the patch which applies to today's git version.
Description: systemd-resolved, sessions, and tmpfiles patches
Author: Russell Coker <russell@coker.com.au>
Last-Update: 2017-03-26
Here's the latest version of my patch to remove all /var/run when it's not
needed. I have removed the subst thing from the patch, but kept a
distro_debian bit that relies on it. So with this patch the policy won't
install if you build it with distro_debian unless you have my subst patch.
Chris, if your automated tests require that it build and install with
distro_debian then skip the patch for sysnetwork.fc.
From Russell Coker
Chris PeBenito
Sugar, David
Nicolas Iooss
Russell Coker
James Carter
Jason Zaman via refpolicy
Luis Ressel
Stephen Smalley
cgzones