[patch 2/2] Use find_task_by_vpid in audit code

The pid to lookup a task by is passed inside audit code via netlink message.

Thanks to Denis Lunev, netlink packets are now (since 2.6.24) _always_
processed in the context of the sending task.  So this is correct to lookup
the task with find_task_by_vpid() here.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

kernel/audit.c

@@ -455,7 +455,7 @@ static int audit_prepare_user_tty(pid_t pid, uid_t loginuid, u32 sessionid)
 	int err;
 
 	read_lock(&tasklist_lock);
-	tsk = find_task_by_pid(pid);
+	tsk = find_task_by_vpid(pid);
 	err = -ESRCH;
 	if (!tsk)
 		goto out;
@@ -871,7 +871,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		struct task_struct *tsk;
 
 		read_lock(&tasklist_lock);
-		tsk = find_task_by_pid(pid);
+		tsk = find_task_by_vpid(pid);
 		if (!tsk)
 			err = -ESRCH;
 		else {
@@ -894,7 +894,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		if (s->enabled != 0 && s->enabled != 1)
 			return -EINVAL;
 		read_lock(&tasklist_lock);
-		tsk = find_task_by_pid(pid);
+		tsk = find_task_by_vpid(pid);
 		if (!tsk)
 			err = -ESRCH;
 		else {