commit af85d1772e31fed34165a1b3decef340cf4080c0 upstream.

The audit_filter_rules() function in auditsc.c used the in_[e]group_p()
functions to check GID/EGID match, but these functions use the current
task's credentials, while the comparison should use the credentials of
the task given to audit_filter_rules() as a parameter (tsk).

Note that we can use group_search(cred->group_info, ...) as a
replacement for both in_group_p and in_egroup_p as these functions only
compare the parameter to cred->fsgid/egid and then call group_search.

In fact, the usage of in_group_p was even more incorrect: it compares to
cred->fsgid (which is usually equal to cred->egid) and not cred->gid.

GitHub issue:
https://github.com/linux-audit/audit-kernel/issues/82

Fixes: 37eebe39c973 ("audit: improve GID/EGID comparation logic")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 43761473c254b45883a64441dd0bc85a42f3645c upstream.

There is a double fetch problem in audit_log_single_execve_arg()
where we first check the execve(2) argumnets for any "bad" characters
which would require hex encoding and then re-fetch the arguments for
logging in the audit record[1].  Of course this leaves a window of
opportunity for an unsavory application to munge with the data.

This patch reworks things by only fetching the argument data once[2]
into a buffer where it is scanned and logged into the audit
records(s).  In addition to fixing the double fetch, this patch
improves on the original code in a few other ways: better handling
of large arguments which require encoding, stricter record length
checking, and some performance improvements (completely unverified,
but we got rid of some strlen() calls, that's got to be a good
thing).

As part of the development of this patch, I've also created a basic
regression test for the audit-testsuite, the test can be tracked on
GitHub at the following link:

 * https://github.com/linux-audit/audit-testsuite/issues/25

[1] If you pay careful attention, there is actually a triple fetch
problem due to a strnlen_user() call at the top of the function.

[2] This is a tiny white lie, we do make a call to strnlen_user()
prior to fetching the argument data.  I don't like it, but due to the
way the audit record is structured we really have no choice unless we
copy the entire argument at once (which would require a rather
wasteful allocation).  The good news is that with this patch the
kernel no longer relies on this strnlen_user() value for anything
beyond recording it in the log, we also update it with a trustworthy
value whenever possible.

Reported-by: Pengfei Wang <wpengfeinudt@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

Fixes an easy DoS and possible information disclosure.

This does nothing about the broken state of x32 auditing.

eparis: If the admin has enabled auditd and has specifically loaded
audit rules.  This bug has been around since before git.  Wow...

Cc: stable@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull audit updates from Eric Paris.

* git://git.infradead.org/users/eparis/audit: (28 commits)
  AUDIT: make audit_is_compat depend on CONFIG_AUDIT_COMPAT_GENERIC
  audit: renumber AUDIT_FEATURE_CHANGE into the 1300 range
  audit: do not cast audit_rule_data pointers pointlesly
  AUDIT: Allow login in non-init namespaces
  audit: define audit_is_compat in kernel internal header
  kernel: Use RCU_INIT_POINTER(x, NULL) in audit.c
  sched: declare pid_alive as inline
  audit: use uapi/linux/audit.h for AUDIT_ARCH declarations
  syscall_get_arch: remove useless function arguments
  audit: remove stray newline from audit_log_execve_info() audit_panic() call
  audit: remove stray newlines from audit_log_lost messages
  audit: include subject in login records
  audit: remove superfluous new- prefix in AUDIT_LOGIN messages
  audit: allow user processes to log from another PID namespace
  audit: anchor all pid references in the initial pid namespace
  audit: convert PPIDs to the inital PID namespace.
  pid: get pid_t ppid of task in init_pid_ns
  audit: rename the misleading audit_get_context() to audit_take_context()
  audit: Add generic compat syscall support
  audit: Add CONFIG_HAVE_ARCH_AUDITSYSCALL
  ...

There's an unnecessary use of a \n in audit_panic.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>

The login uid change record does not include the selinux context of the
task logging in.  Add that information.

(Updated from 2011-01: RHBZ:670328 -- RGB)

Reported-by: Steve Grubb <sgrubb@redhat.com>
Acked-by: James Morris <jmorris@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Aristeu Rozanski <arozansk@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>

The new- prefix on ses and auid are un-necessary and break ausearch.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>

Store and log all PIDs with reference to the initial PID namespace and
use the access functions task_pid_nr() and task_tgid_nr() for task->pid
and task->tgid.

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
(informed by ebiederman's c776b5d2)
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>

sys_getppid() returns the parent pid of the current process in its own pid
namespace.  Since audit filters are based in the init pid namespace, a process
could avoid a filter or trigger an unintended one by being in an alternate pid
namespace or log meaningless information.

Switch to task_ppid_nr() for PPIDs to anchor all audit filters in the
init_pid_ns.

(informed by ebiederman's 6c621b7e)
Cc: stable@vger.kernel.org
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>

"get" usually implies incrementing a refcount into a structure to indicate a
reference being held by another part of code.

Change this function name to indicate it is in fact being taken from it,
returning the value while clearing it in the supplying structure.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>