[PATCH] Support for auditing on the actions of a not-yet-executed process.
by Peter Moody
eg:
-a exit,always -F arch=b64 -S socket -F 'a0!=1' -F exe=/bin/bash -F success=1
to see instances of /bin/bash opening a non-local socket. Or
-a exit,always -F arch=b64 -S socket -F 'a0!=1' -F exe_children=/bin/bash -F success=1
to instances of /bin/bash, and any descendant processes, opening a non local socket.
proposed https://www.redhat.com/archives/linux-audit/2012-June/msg00002.html
and it seemed like there was interest.
Signed-off-by: Peter Moody <pmoody(a)google.com>
---
trunk/lib/errormsg.h | 2 +-
trunk/lib/fieldtab.h | 2 ++
trunk/lib/libaudit.c | 11 +++++++++++
trunk/lib/libaudit.h | 7 ++++++-
4 files changed, 20 insertions(+), 2 deletions(-)
diff --git a/trunk/lib/errormsg.h b/trunk/lib/errormsg.h
index 4d996d5..cd595ec 100644
--- a/trunk/lib/errormsg.h
+++ b/trunk/lib/errormsg.h
@@ -51,7 +51,7 @@ static const struct msg_tab err_msgtab[] = {
{ -15, 2, "-F unknown errno -"},
{ -16, 2, "-F unknown file type - " },
{ -17, 1, "can only be used with exit and entry filter list" },
- { -18, 1, "" }, // Unused
+ { -18, 1, "only takes = operator" },
{ -19, 0, "Key field needs a watch or syscall given prior to it" },
{ -20, 2, "-F missing value after operation for" },
{ -21, 2, "-F value should be number for" },
diff --git a/trunk/lib/fieldtab.h b/trunk/lib/fieldtab.h
index c0432cc..245b541 100644
--- a/trunk/lib/fieldtab.h
+++ b/trunk/lib/fieldtab.h
@@ -66,3 +66,5 @@ _S(AUDIT_ARG3, "a3" )
_S(AUDIT_FILTERKEY, "key" )
_S(AUDIT_FIELD_COMPARE, "field_compare" )
+_S(AUDIT_EXE, "exe" )
+_S(AUDIT_EXE_CHILDREN, "exe_children" )
diff --git a/trunk/lib/libaudit.c b/trunk/lib/libaudit.c
index 20eaf5f..06eed86 100644
--- a/trunk/lib/libaudit.c
+++ b/trunk/lib/libaudit.c
@@ -1400,6 +1400,17 @@ int audit_rule_fieldpair_data(struct audit_rule_data **rulep, const char *pair,
else
return -21;
break;
+ case AUDIT_EXE_CHILDREN:
+ case AUDIT_EXE:
+ {
+ struct stat buf;
+ if ((stat(v, &buf)) < 0)
+ return -2;
+ if (op != AUDIT_EQUAL)
+ return -18;
+ rule->values[rule->field_count] = (unsigned long)buf.st_ino;
+ }
+ break;
case AUDIT_DEVMAJOR...AUDIT_INODE:
case AUDIT_SUCCESS:
if (flags != AUDIT_FILTER_EXIT)
diff --git a/trunk/lib/libaudit.h b/trunk/lib/libaudit.h
index 89dd588..2c8a802 100644
--- a/trunk/lib/libaudit.h
+++ b/trunk/lib/libaudit.h
@@ -243,6 +243,12 @@ extern "C" {
#ifndef AUDIT_FIELD_COMPARE
#define AUDIT_FIELD_COMPARE 111
#endif
+#ifndef AUDIT_EXE
+#define AUDIT_EXE 112
+#endif
+#ifndef AUDIT_EXE_CHILDREN
+#define AUDIT_EXE_CHILDREN 113
+#endif
#ifndef AUDIT_COMPARE_UID_TO_OBJ_UID
#define AUDIT_COMPARE_UID_TO_OBJ_UID 1
@@ -524,4 +530,3 @@ extern void audit_rule_free_data(struct audit_rule_data *rule);
#endif
#endif
-
--
1.7.7.3
10 years, 6 months
[PATCH] audit: audit on the future execution of a binary.
by Peter Moody
This adds the ability audit the actions of a not-yet-running process,
as well as the children of a not-yet-running process.
Signed-off-by: Peter Moody <pmoody(a)google.com>
---
include/linux/audit.h | 2 ++
kernel/auditfilter.c | 6 ++++++
kernel/auditsc.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 55 insertions(+), 0 deletions(-)
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 22f292a..5506cb1 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -260,6 +260,8 @@
#define AUDIT_OBJ_UID 109
#define AUDIT_OBJ_GID 110
#define AUDIT_FIELD_COMPARE 111
+#define AUDIT_EXE 112
+#define AUDIT_EXE_CHILDREN 113
#define AUDIT_ARG0 200
#define AUDIT_ARG1 (AUDIT_ARG0+1)
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index a6c3f1a..1e6c571 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -546,6 +546,12 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
if (f->val > AUDIT_MAX_FIELD_COMPARE)
goto exit_free;
break;
+ case AUDIT_EXE:
+ case AUDIT_EXE_CHILDREN:
+ if (f->op != Audit_equal) {
+ goto exit_free;
+ }
+ break;
default:
goto exit_free;
}
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 4b96415..9cebe95 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -46,6 +46,7 @@
#include <asm/types.h>
#include <linux/atomic.h>
#include <linux/fs.h>
+#include <linux/dcache.h>
#include <linux/namei.h>
#include <linux/mm.h>
#include <linux/export.h>
@@ -68,6 +69,7 @@
#include <linux/capability.h>
#include <linux/fs_struct.h>
#include <linux/compat.h>
+#include <linux/sched.h>
#include "audit.h"
@@ -592,6 +594,35 @@ static int audit_field_compare(struct task_struct *tsk,
return 0;
}
+int audit_match_exe(struct task_struct *tsk, struct audit_field *f)
+{
+ int result = 0;
+ struct mm_struct *mm;
+ struct vm_area_struct *vma;
+
+ if (!tsk)
+ goto out;
+
+ mm = tsk->mm;
+ if (!mm)
+ goto out;
+
+ down_read(&mm->mmap_sem);
+ vma = mm->mmap;
+ while (vma) {
+ if ((vma->vm_flags & VM_EXECUTABLE) &&
+ vma->vm_file) {
+ struct inode *ino = vma->vm_file->f_path.dentry->d_inode;
+ result = audit_comparator(ino->i_ino, f->op, f->val);
+ break;
+ }
+ vma = vma->vm_next;
+ }
+ up_read(&mm->mmap_sem);
+out:
+ return result;
+}
+
/* Determine if any context name data matches a rule's watch data */
/* Compare a task_struct with an audit_rule. Return 1 on match, 0
* otherwise.
@@ -629,6 +660,22 @@ static int audit_filter_rules(struct task_struct *tsk,
result = audit_comparator(ctx->ppid, f->op, f->val);
}
break;
+ case AUDIT_EXE:
+ result = audit_match_exe(tsk, f);
+ break;
+ case AUDIT_EXE_CHILDREN:
+ {
+ struct task_struct *ptsk;
+ for (ptsk = tsk;
+ ptsk->parent->pid > 0;
+ ptsk = find_task_by_vpid(ptsk->parent->pid)) {
+ if (audit_match_exe(ptsk, f)) {
+ ++result;
+ break;
+ }
+ }
+ }
+ break;
case AUDIT_UID:
result = audit_comparator(cred->uid, f->op, f->val);
break;
--
1.7.7.3
11 years, 1 month
user message limits
by LC Bruzenak
I know I can go look at the code, however I figured I'd ask here first
about the limits on the user message in both audit_log_user_message and
ausearch.
With audit_log_user_message the maximum length allowed appears to be
around MAX_AUDIT_MESSAGE_LENGTH-100. I think it may depend on the
executable name length (and other stuff auto-pushed into the string)
which is why I say "around".
Even when I get a successful return value (from audit_log_user_message),
I don't get my string back out in "ausearch" unless it is WAY smaller -
~1K or less I think.
Any ideas/thoughts?
This is the latest (1.7.11-2) audit package.
Thx,
LCB.
--
LC (Lenny) Bruzenak
lenny(a)magitekltd.com
11 years, 1 month
[PATCH] audit: armv6l added to machintab for Raspberry Pi
by Nathaniel Husted
This patch was created to add the armv6l (Raspberry Pi) platform to
audit. Without the patch auditctl errors that it cannot find the
machine type whenever loading the rules file. This patch was tested on
a physical raspberry pi board. The environment was the latest Raspbian
distribution and the latest audit from the SVN. Upon the loading of
the rules file, I was able to test the clone, execve, and fork system
calls using a back patch for the Raspberry Pi kernel (they're still on
3.2).
Signed-off-by: Nathaniel Husted <nhusted(a)gmail.com>
---
diff --git a/lib/machinetab.h b/lib/machinetab.h
index 378db6e..60509c4 100644
--- a/lib/machinetab.h
+++ b/lib/machinetab.h
@@ -37,4 +37,5 @@ _S(MACH_ALPHA, "alpha" )
_S(MACH_ARMEB, "armeb" )
_S(MACH_ARMEB, "armv5tejl")
_S(MACH_ARMEB, "armv7l")
+_S(MACH_ARMEB, "armv6l")
#endif
11 years, 12 months
[PATCH 0/5] Build time disabling of auditd network listener
by Tyler Hicks
Hello Steve - This is a patch set that allows --disable-listener to be passed
to the configure script to disable the auditd network listener code at build
time. The reasoning is that a large number of users do not need centralized
audit logging and removing the network listening code from a root-owned auditd
process is appealing from a security perspective.
The existing implementation clearly does not initialize the listener when
tcp_listen_port is undefined in auditd.conf, but I still think there is value
in not having the listening code present in all auditd installations.
The first three patches in the set are refactoring patches to move nearly all of
the listening code into auditd-listen.c in order to minimize the number of
ifdefs that would need to be scattered throughout C source files. The fourth
patch is an optional cleanup patch. The last patch introduces the
--disable-listener option.
The auditd listener code is still enabled by default so that existing distro
packaging recipes will not need to be updated.
I look forward to your feedback. Thanks!
Tyler
11 years, 12 months
linux-audit: reconstruct path names from syscall events?
by John Feuerstein
Hi,
I would like to audit all changes to a directory tree using the linux
auditing system[1].
# auditctl -a exit,always -F dir=/etc/ -F perm=wa
It seems like the GNU coreutils are enough to break the audit trail.
The resulting SYSCALL events provide CWD and multiple PATH records,
depending on the syscall. If one of the PATH records is relative, I can
reconstruct the absolute path using the CWD record.
However, that does not work for the whole *at syscall family
(unlinkat(2), renameat(2), linkat(2), ...); accepting paths relative to
a given directory file descriptor. GNU coreutils are prominent users,
for example "rm -r" making use of unlinkat(2) to prevent races.
Things like dup(2) and fd passing via unix domain sockets come to mind.
It's the same old story again: mapping fds to path names is ambiguous at
best, if not impossible.
I wonder why such incomplete file system auditing rules are considered
sufficient in the CAPP/LSPP/NISPOM/STIG rulesets?
Here's a simplified example:
$ cd /tmp
$ mkdir dir
$ touch dir/file
$ ls -ldi /tmp /tmp/dir /tmp/dir/file
2057 drwxrwxrwt 9 root root 380 Sep 17 00:02 /tmp
58781 drwxr-xr-x 2 john john 40 Sep 17 00:02 /tmp/dir
56228 -rw-r--r-- 1 john john 0 Sep 17 00:02 /tmp/dir/file
$ cat > unlinkat.c
#include <unistd.h>
#include <fcntl.h>
int main(int argc, char **argv)
{
int dirfd = open("dir", O_RDONLY);
unlinkat(dirfd, "file", 0);
return 0;
}
^D
$ make unlinkat
cc unlinkat.c -o unlinkat
$ sudo autrace ./unlinkat
Waiting to execute: ./unlinkat
Cleaning up...
Trace complete. You can locate the records with 'ausearch -i -p 32121'
$ ls -li dir
total 0
Now, looking at the resulting raw SYSCALL event for unlinkat(2):
type=SYSCALL msg=audit(1316210542.899:779): arch=c000003e syscall=263 success=yes exit=0 a0=3 a1=400690 a2=0 a3=0 items=2 ppid=32106 pid=32121 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts12 ses=36 comm="unlinkat" exe="/tmp/unlinkat" key=(null)
type=CWD msg=audit(1316210542.899:779): cwd="/tmp"
type=PATH msg=audit(1316210542.899:779): item=0 name="/tmp" inode=58781 dev=00:0e mode=040755 ouid=1000 ogid=1000 rdev=00:00
type=PATH msg=audit(1316210542.899:779): item=1 name="file" inode=56228 dev=00:0e mode=0100644 ouid=1000 ogid=1000 rdev=00:00
type=EOE msg=audit(1316210542.899:779):
- From this event alone, there's no way to answer "Who unlinked
/tmp/dir/file?". For what it's worth, the provided path names would be
exactly the same if we had unlinked "/tmp/dir/dir/dir/dir/dir/file".
- PATH item 0 reports the inode of "/tmp/dir" (58781, see ls output
above), however, the reported path name is "/tmp" (bug?).
In this example I've used autrace, which traces everything, so I could
possibly search for a previous open(2) of inode 58781. And indeed, there
it is:
type=SYSCALL msg=audit(1316210542.899:778): arch=c000003e syscall=2 success=yes exit=3 a0=40068c a1=0 a2=7fff22724fc8 a3=0 items=1 ppid=32106 pid=32121 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts12 ses=36 comm="unlinkat" exe="/tmp/unlinkat" key=(null)
type=CWD msg=audit(1316210542.899:778): cwd="/tmp"
type=PATH msg=audit(1316210542.899:778): item=0 name="dir" inode=58781 dev=00:0e mode=040755 ouid=1000 ogid=1000 rdev=00:00
type=EOE msg=audit(1316210542.899:778):
Great, so inode 58781 was opened using "/tmp/dir", and therefore, the relative
path "file" given to unlinkat(2) above could possibly translate to
"/tmp/dir/path"... not really feeling confident here.
- All file system auditing rules in various rulesets and the examples in
the documentation add the "-F perm=wa" (or similar) filter, so the
open(2) wouldn't even make it into the audit trail.
- If you can handle the volume and log all open(2), what happens if the
open(2) was done hours, days, weeks, ... ago?
- What if the open(2) was done by another process which passed the fd
on a unix domain socket?
It looks like the kernel auditing code should provide
... item=0 name="/tmp/dir" inode=58781 ...
in the unlinkat(2) syscall event above. Looking up the unlinkat(2)
documentation:
int unlinkat(int dirfd, const char *pathname, int flags);
If the pathname given in pathname is relative, then it is
interpreted relative to the directory referred to by the file
descriptor dirfd (rather than relative to the current working
directory of the calling process, as is done by unlink(2) and
rmdir(2) for a relative pathname).
If the pathname given in pathname is relative and dirfd is the
special value AT_FDCWD, then pathname is interpreted relative
to the current working directory of the calling process (like
unlink(2) and rmdir(2)).
As you might see, there's not only the fd->pathname problem, but
also the special case for AT_FDCWD. In this case the kernel side should
probably just duplicate CWD's path name into item 0's path name. But
that's just unlinkat(2), there are a lot more.
What am I missing here? Is there no way to audit a directory tree?
I've looked at alternatives: Inotify watches won't scale to big trees
and events lack so much detail that they can't be used for auditing.
Fanotify, while providing the pid, still lacks a lot of events and
passes fds; the example code relies on readlink("/proc/self/fd/...").
Thanks,
John
[1] http://people.redhat.com/sgrubb/audit/
--
John Feuerstein <john(a)feurix.com>
12 years
[PATCH 0/3] audit: minor audit cleanups
by Jeff Layton
These patches are some cleanups suggested by HCH when he was reviewing
my audit set that went into 3.7. They should introduce no behavioral
changes. They're just cleanups for clarity's sake.
I think the first patch in the series makes a lot of sense. The last two
patches don't seem to provide as much improvement in clarity to me. I'm
not opposed to including them if others think they do, so I'll post
them here so we can debate their merits.
These (or some subset of these) are probably appropriate for 3.8.
Jeff Layton (3):
audit: eliminate optional dentry argument to audit_copy_inode
audit: break the setup of the audit_name out of audit_inode and into
separate function
audit: break up __audit_inode into two functions
fs/open.c | 4 ++--
fs/xattr.c | 8 ++++----
include/linux/audit.h | 11 +++++++++-
ipc/mqueue.c | 4 ++--
kernel/auditsc.c | 57 ++++++++++++++++++++++++++++++++++++---------------
5 files changed, 59 insertions(+), 25 deletions(-)
--
1.7.11.7
12 years
[PATCH] Audit: do not print error when SELinux disabled
by Eric Paris
RHBZ: 785936
About to be posted upstream
If the audit system collects a record about one process sending a signal
to another process it includes in that collection the 'secid' or 'an int
used to represet an SELinux label.' If SELinux is disabled it will
collect a 0. The problem is that when we attempt to print that record
we ask the LSM to convert the secid back to a string. Since there is no
LSM it returns EOPNOTSUPP.
Most code in the audit system checks if the secid is 0 and does not
print LSM info in that case. The signal information code however forgot
that check. Thus users will see a message in syslog indicating that
converting the sid to string failed. Add the right check.
Signed-off-by: Eric Paris <eparis(a)redhat.com>
---
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 857f2e2..1f5cc03 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1195,12 +1195,14 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid, auid,
uid, sessionid);
- if (security_secid_to_secctx(sid, &ctx, &len)) {
- audit_log_format(ab, " obj=(none)");
- rc = 1;
- } else {
- audit_log_format(ab, " obj=%s", ctx);
- security_release_secctx(ctx, len);
+ if (sid) {
+ if (security_secid_to_secctx(sid, &ctx, &len)) {
+ audit_log_format(ab, " obj=(none)");
+ rc = 1;
+ } else {
+ audit_log_format(ab, " obj=%s", ctx);
+ security_release_secctx(ctx, len);
+ }
}
audit_log_format(ab, " ocomm=");
audit_log_untrustedstring(ab, comm);
12 years
Help on Audit Rules
by Koresh...
Hi Team,
I have enabled the audit logs recently ... Currently the auditd daemon is
logging all the event and syscalls done based on default rule set ...
But currently it only record the events done by the root user or by the
sudo ...
Need your help to configure the same for Group wise ... so that i can track
the group wise events done , rather then adding a rule for each individual
users.
--
Thanks & Regards,
- Koresh
12 years
[PATCH] audit: grab a reference to context->pwd when it's cached
by Peter Moody
On certain systems, in certain pathalogical cases, current's cwd can
be deleted while we're still processing a syscall. This should prevent
the system from evicting the inode while we're still referencing it.
This seems to fix the bug I reported here:
https://www.redhat.com/archives/linux-audit/2012-August/msg00017.html
Signed-off-by: Peter Moody <pmoody(a)google.com>
---
kernel/auditsc.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 4b96415..e86b8b9 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2064,6 +2064,7 @@ void __audit_getname(const char *name)
if (!context->pwd.dentry)
get_fs_pwd(current->fs, &context->pwd);
+ path_get(&context->pwd);
}
/* audit_putname - intercept a putname request
@@ -2091,6 +2092,7 @@ void audit_putname(const char *name)
n->name, n->name ?: "(null)");
}
#endif
+ path_put(&context->pwd);
__putname(name);
}
#if AUDIT_DEBUG
--
1.7.7.3
12 years
