audit: convert PPIDs to the inital PID namespace.

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>

diff --git a/kernel/audit.c b/kernel/audit.c
index 7b44bd47759c6ad641b34faade4376e61bc609a4..e1e1b2137048d186a7b59e1ff70c9aedc5881155 100644 (file)
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1819,10 +1819,10 @@ void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
        spin_unlock_irq(&tsk->sighand->siglock);
 
        audit_log_format(ab,
-                        " ppid=%ld pid=%d auid=%u uid=%u gid=%u"
+                        " ppid=%d pid=%d auid=%u uid=%u gid=%u"
                         " euid=%u suid=%u fsuid=%u"
                         " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
-                        sys_getppid(),
+                        task_ppid_nr(tsk),
                         tsk->pid,
                         from_kuid(&init_user_ns, audit_get_loginuid(tsk)),
                         from_kuid(&init_user_ns, cred->uid),

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 57bf178ca7d58dfa90facaa48f4d77b983014df4..a6cf7ab56e61ebbe340328b575792c84f9fc8f65 100644 (file)
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -465,7 +465,7 @@ static int audit_filter_rules(struct task_struct *tsk,
                case AUDIT_PPID:
                        if (ctx) {
                                if (!ctx->ppid)
-                                       ctx->ppid = sys_getppid();
+                                       ctx->ppid = task_ppid_nr(tsk);
                                result = audit_comparator(ctx->ppid, f->op, f->val);
                        }
                        break;