From: Andrew Morton <akpm@osdl.org>

Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 kernel/taskstats.c |   48 ++++++++++++++++++++++++++-----------------
 1 file changed, 30 insertions(+), 18 deletions(-)

diff -puN kernel/taskstats.c~per-task-delay-accounting-taskstats-interface-control-exit-data-through-cpumasks-fix kernel/taskstats.c
--- a/kernel/taskstats.c~per-task-delay-accounting-taskstats-interface-control-exit-data-through-cpumasks-fix
+++ a/kernel/taskstats.c
@@ -299,6 +299,28 @@ cleanup:
 	return 0;
 }
 
+static int parse(struct nlattr *na, cpumask_t *mask)
+{
+	char *data;
+	int len;
+	int ret;
+
+	if (na == NULL)
+		return 1;
+	len = nla_len(na);
+	if (len > TASKSTATS_CPUMASK_MAXLEN)
+		return -E2BIG;
+	if (len < 1)
+		return -EINVAL;
+	data = kmalloc(len, GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+	nla_strlcpy(data, na, len);
+	ret = cpulist_parse(data, *mask);
+	kfree(data);
+	return ret;
+}
+
 static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
 {
 	int rc = 0;
@@ -309,27 +331,17 @@ static int taskstats_user_cmd(struct sk_
 	struct nlattr *na;
 	cpumask_t mask;
 
-	if (info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK]) {
-		na = info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK];
-		if (nla_len(na) > TASKSTATS_CPUMASK_MAXLEN)
-			return -E2BIG;
-		rc = cpulist_parse((char *)nla_data(na), mask);
-		if (rc)
-			return rc;
-		rc = add_del_listener(info->snd_pid, &mask, REGISTER);
+	rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], &mask);
+	if (rc < 0)
 		return rc;
-	}
+	if (rc == 0)
+		return add_del_listener(info->snd_pid, &mask, REGISTER);
 
-	if (info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK]) {
-		na = info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK];
-		if (nla_len(na) > TASKSTATS_CPUMASK_MAXLEN)
-			return -E2BIG;
-		rc = cpulist_parse((char *)nla_data(na), mask);
-		if (rc)
-			return rc;
-		rc = add_del_listener(info->snd_pid, &mask, DEREGISTER);
+	rc = parse(info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK], &mask);
+	if (rc < 0)
 		return rc;
-	}
+	if (rc == 0)
+		return add_del_listener(info->snd_pid, &mask, DEREGISTER);
 
 	/*
 	 * Size includes space for nested attributes
_