3 files changed, 16 insertions, 39 deletions

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index a990824..2aeb6ff 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -349,16 +349,10 @@ static ssize_t blk_msg_write(struct file *filp, const char __user *buffer,
 	if (count >= BLK_TN_MAX_MSG)
 		return -EINVAL;
 
-	msg = kmalloc(count + 1, GFP_KERNEL);
-	if (msg == NULL)
-		return -ENOMEM;
-
-	if (copy_from_user(msg, buffer, count)) {
-		kfree(msg);
-		return -EFAULT;
-	}
+	msg = memdup_user_nul(buffer, count);
+	if (IS_ERR(msg))
+		return PTR_ERR(msg);
 
-	msg[count] = '\0';
 	bt = filp->private_data;
 	__trace_note_message(bt, "%s", msg);
 	kfree(msg);
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 4f6ef69..f333e57 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1340,15 +1340,9 @@ event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 	if (cnt >= PAGE_SIZE)
 		return -EINVAL;
 
-	buf = (char *)__get_free_page(GFP_TEMPORARY);
-	if (!buf)
-		return -ENOMEM;
-
-	if (copy_from_user(buf, ubuf, cnt)) {
-		free_page((unsigned long) buf);
-		return -EFAULT;
-	}
-	buf[cnt] = '\0';
+	buf = memdup_user_nul(ubuf, cnt);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
 
 	mutex_lock(&event_mutex);
 	file = event_file_data(filp);
@@ -1356,7 +1350,7 @@ event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 		err = apply_event_filter(file, buf);
 	mutex_unlock(&event_mutex);
 
-	free_page((unsigned long) buf);
+	kfree(buf);
 	if (err < 0)
 		return err;
 
@@ -1507,18 +1501,12 @@ subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 	if (cnt >= PAGE_SIZE)
 		return -EINVAL;
 
-	buf = (char *)__get_free_page(GFP_TEMPORARY);
-	if (!buf)
-		return -ENOMEM;
-
-	if (copy_from_user(buf, ubuf, cnt)) {
-		free_page((unsigned long) buf);
-		return -EFAULT;
-	}
-	buf[cnt] = '\0';
+	buf = memdup_user_nul(ubuf, cnt);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
 
 	err = apply_subsystem_event_filter(dir, buf);
-	free_page((unsigned long) buf);
+	kfree(buf);
 	if (err < 0)
 		return err;
 
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 42a4009..4b5e8ed6 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -237,28 +237,23 @@ static ssize_t event_trigger_regex_write(struct file *file,
 	if (cnt >= PAGE_SIZE)
 		return -EINVAL;
 
-	buf = (char *)__get_free_page(GFP_TEMPORARY);
-	if (!buf)
-		return -ENOMEM;
+	buf = memdup_user_nul(ubuf, cnt);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
 
-	if (copy_from_user(buf, ubuf, cnt)) {
-		free_page((unsigned long)buf);
-		return -EFAULT;
-	}
-	buf[cnt] = '\0';
 	strim(buf);
 
 	mutex_lock(&event_mutex);
 	event_file = event_file_data(file);
 	if (unlikely(!event_file)) {
 		mutex_unlock(&event_mutex);
-		free_page((unsigned long)buf);
+		kfree(buf);
 		return -ENODEV;
 	}
 	ret = trigger_process_regex(event_file, buf);
 	mutex_unlock(&event_mutex);
 
-	free_page((unsigned long)buf);
+	kfree(buf);
 	if (ret < 0)
 		goto out;