BACKPORT: audit: consistently record PIDs with task_tgid_nr()

Unfortunately we record PIDs in audit records using a variety of
methods despite the correct way being the use of task_tgid_nr().
This patch converts all of these callers, except for the case of
AUDIT_SET in audit_receive_msg() (see the comment in the code).

Reported-by: Jeff Vander Stoep <jeffv@google.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

Bug: 28952093

(cherry picked from commit fa2bea2f5cca5b8d4a3e5520d2e8c0ede67ac108)
Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
Change-Id: I36508a25c957f5108299e68a3b0f627c94eb27eb
Signed-off-by: Joe Maples <joe@frap129.org>

2 files changed, 13 insertions, 7 deletions

diff --git a/kernel/audit.c b/kernel/audit.c
index 6c874e506..53e987df0 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -701,6 +701,12 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 				return err;
 		}
 		if (status_get->mask & AUDIT_STATUS_PID) {
+			/* NOTE: we are using task_tgid_vnr() below because
+			 *       the s.pid value is relative to the namespace
+			 *       of the caller; at present this doesn't matter
+			 *       much since you can really only run auditd
+			 *       from the initial pid namespace, but something
+			 *       to keep in mind if this changes */
 			int new_pid = status_get->pid;
 
 			if (audit_enabled != AUDIT_OFF)
@@ -1632,7 +1638,7 @@ void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
 			 " euid=%u suid=%u fsuid=%u"
 			 " egid=%u sgid=%u fsgid=%u ses=%u tty=%s",
 			 sys_getppid(),
-			 tsk->pid,
+			 task_tgid_nr(tsk),
 			 from_kuid(&init_user_ns, audit_get_loginuid(tsk)),
 			 from_kuid(&init_user_ns, cred->uid),
 			 from_kgid(&init_user_ns, cred->gid),
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index f3286c7d5..c1532eaeb 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -469,7 +469,7 @@ static int audit_filter_rules(struct task_struct *tsk,
 
 		switch (f->type) {
 		case AUDIT_PID:
-			result = audit_comparator(tsk->pid, f->op, f->val);
+			result = audit_comparator(task_tgid_nr(tsk), f->op, f->val);
 			break;
 		case AUDIT_PPID:
 			if (ctx) {
@@ -2001,7 +2001,7 @@ int audit_set_loginuid(kuid_t loginuid)
 			audit_log_format(ab, "login pid=%d uid=%u "
 				"old auid=%u new auid=%u"
 				" old ses=%u new ses=%u",
-				task->pid,
+				task_tgid_nr(task),
 				from_kuid(&init_user_ns, task_uid(task)),
 				from_kuid(&init_user_ns, task->loginuid),
 				from_kuid(&init_user_ns, loginuid),
@@ -2209,7 +2209,7 @@ void __audit_ptrace(struct task_struct *t)
 {
 	struct audit_context *context = current->audit_context;
 
-	context->target_pid = t->pid;
+	context->target_pid = task_tgid_nr(t);
 	context->target_auid = audit_get_loginuid(t);
 	context->target_uid = task_uid(t);
 	context->target_sessionid = audit_get_sessionid(t);
@@ -2234,7 +2234,7 @@ int __audit_signal_info(int sig, struct task_struct *t)
 
 	if (audit_pid && t->tgid == audit_pid) {
 		if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1 || sig == SIGUSR2) {
-			audit_sig_pid = tsk->pid;
+			audit_sig_pid = task_tgid_nr(tsk);
 			if (uid_valid(tsk->loginuid))
 				audit_sig_uid = tsk->loginuid;
 			else
@@ -2339,7 +2339,7 @@ void __audit_log_capset(pid_t pid,
 		       const struct cred *new, const struct cred *old)
 {
 	struct audit_context *context = current->audit_context;
-	context->capset.pid = pid;
+	context->capset.pid = task_tgid_nr(current);
 	context->capset.cap.effective   = new->cap_effective;
 	context->capset.cap.inheritable = new->cap_effective;
 	context->capset.cap.permitted   = new->cap_permitted;
@@ -2370,7 +2370,7 @@ static void audit_log_task(struct audit_buffer *ab)
 			 from_kgid(&init_user_ns, gid),
 			 sessionid);
 	audit_log_task_context(ab);
-	audit_log_format(ab, " pid=%d comm=", current->pid);
+	audit_log_format(ab, " pid=%d comm=", task_tgid_nr(current));
 	audit_log_untrustedstring(ab, current->comm);
 }