diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index dc6858d..5faf89a 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2047,9 +2047,8 @@
 		  void *data)
 {
 	int *i, vleft, first = 1, err = 0;
-	unsigned long page = 0;
 	size_t left;
-	char *kbuf;
+	char *kbuf = NULL, *p;
 	
 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
 		*lenp = 0;
@@ -2078,15 +2077,9 @@
 
 		if (left > PAGE_SIZE - 1)
 			left = PAGE_SIZE - 1;
-		page = __get_free_page(GFP_TEMPORARY);
-		kbuf = (char *) page;
-		if (!kbuf)
-			return -ENOMEM;
-		if (copy_from_user(kbuf, buffer, left)) {
-			err = -EFAULT;
-			goto free;
-		}
-		kbuf[left] = 0;
+		p = kbuf = memdup_user_nul(buffer, left);
+		if (IS_ERR(kbuf))
+			return PTR_ERR(kbuf);
 	}
 
 	for (; left && vleft--; i++, first=0) {
@@ -2094,11 +2087,11 @@
 		bool neg;
 
 		if (write) {
-			left -= proc_skip_spaces(&kbuf);
+			left -= proc_skip_spaces(&p);
 
 			if (!left)
 				break;
-			err = proc_get_long(&kbuf, &left, &lval, &neg,
+			err = proc_get_long(&p, &left, &lval, &neg,
 					     proc_wspace_sep,
 					     sizeof(proc_wspace_sep), NULL);
 			if (err)
@@ -2125,10 +2118,9 @@
 	if (!write && !first && left && !err)
 		err = proc_put_char(&buffer, &left, '\n');
 	if (write && !err && left)
-		left -= proc_skip_spaces(&kbuf);
-free:
+		left -= proc_skip_spaces(&p);
 	if (write) {
-		free_page(page);
+		kfree(kbuf);
 		if (first)
 			return err ? : -EINVAL;
 	}
@@ -2310,9 +2302,8 @@
 {
 	unsigned long *i, *min, *max;
 	int vleft, first = 1, err = 0;
-	unsigned long page = 0;
 	size_t left;
-	char *kbuf;
+	char *kbuf = NULL, *p;
 
 	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
 		*lenp = 0;
@@ -2340,15 +2331,9 @@
 
 		if (left > PAGE_SIZE - 1)
 			left = PAGE_SIZE - 1;
-		page = __get_free_page(GFP_TEMPORARY);
-		kbuf = (char *) page;
-		if (!kbuf)
-			return -ENOMEM;
-		if (copy_from_user(kbuf, buffer, left)) {
-			err = -EFAULT;
-			goto free;
-		}
-		kbuf[left] = 0;
+		p = kbuf = memdup_user_nul(buffer, left);
+		if (IS_ERR(kbuf))
+			return PTR_ERR(kbuf);
 	}
 
 	for (; left && vleft--; i++, first = 0) {
@@ -2357,9 +2342,9 @@
 		if (write) {
 			bool neg;
 
-			left -= proc_skip_spaces(&kbuf);
+			left -= proc_skip_spaces(&p);
 
-			err = proc_get_long(&kbuf, &left, &val, &neg,
+			err = proc_get_long(&p, &left, &val, &neg,
 					     proc_wspace_sep,
 					     sizeof(proc_wspace_sep), NULL);
 			if (err)
@@ -2385,10 +2370,9 @@
 	if (!write && !first && left && !err)
 		err = proc_put_char(&buffer, &left, '\n');
 	if (write && !err)
-		left -= proc_skip_spaces(&kbuf);
-free:
+		left -= proc_skip_spaces(&p);
 	if (write) {
-		free_page(page);
+		kfree(kbuf);
 		if (first)
 			return err ? : -EINVAL;
 	}
@@ -2650,34 +2634,27 @@
 	}
 
 	if (write) {
-		unsigned long page = 0;
-		char *kbuf;
+		char *kbuf, *p;
 
 		if (left > PAGE_SIZE - 1)
 			left = PAGE_SIZE - 1;
 
-		page = __get_free_page(GFP_TEMPORARY);
-		kbuf = (char *) page;
-		if (!kbuf)
-			return -ENOMEM;
-		if (copy_from_user(kbuf, buffer, left)) {
-			free_page(page);
-			return -EFAULT;
-                }
-		kbuf[left] = 0;
+		p = kbuf = memdup_user_nul(buffer, left);
+		if (IS_ERR(kbuf))
+			return PTR_ERR(kbuf);
 
 		tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
 				     GFP_KERNEL);
 		if (!tmp_bitmap) {
-			free_page(page);
+			kfree(kbuf);
 			return -ENOMEM;
 		}
-		proc_skip_char(&kbuf, &left, '\n');
+		proc_skip_char(&p, &left, '\n');
 		while (!err && left) {
 			unsigned long val_a, val_b;
 			bool neg;
 
-			err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
+			err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
 					     sizeof(tr_a), &c);
 			if (err)
 				break;
@@ -2688,12 +2665,12 @@
 
 			val_b = val_a;
 			if (left) {
-				kbuf++;
+				p++;
 				left--;
 			}
 
 			if (c == '-') {
-				err = proc_get_long(&kbuf, &left, &val_b,
+				err = proc_get_long(&p, &left, &val_b,
 						     &neg, tr_b, sizeof(tr_b),
 						     &c);
 				if (err)
@@ -2704,16 +2681,16 @@
 					break;
 				}
 				if (left) {
-					kbuf++;
+					p++;
 					left--;
 				}
 			}
 
 			bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
 			first = 0;
-			proc_skip_char(&kbuf, &left, '\n');
+			proc_skip_char(&p, &left, '\n');
 		}
-		free_page(page);
+		kfree(kbuf);
 	} else {
 		unsigned long bit_a, bit_b = 0;
 
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 @@
 	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 @@
 		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 @@
 	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 @@
 	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;
 
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 88fefa6..9bafc21 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -602,8 +602,7 @@
 	struct uid_gid_map new_map;
 	unsigned idx;
 	struct uid_gid_extent *extent = NULL;
-	unsigned long page = 0;
-	char *kbuf, *pos, *next_line;
+	char *kbuf = NULL, *pos, *next_line;
 	ssize_t ret = -EINVAL;
 
 	/*
@@ -638,23 +637,18 @@
 	if (cap_valid(cap_setid) && !file_ns_capable(file, ns, CAP_SYS_ADMIN))
 		goto out;
 
-	/* Get a buffer */
-	ret = -ENOMEM;
-	page = __get_free_page(GFP_TEMPORARY);
-	kbuf = (char *) page;
-	if (!page)
-		goto out;
-
 	/* Only allow < page size writes at the beginning of the file */
 	ret = -EINVAL;
 	if ((*ppos != 0) || (count >= PAGE_SIZE))
 		goto out;
 
 	/* Slurp in the user data */
-	ret = -EFAULT;
-	if (copy_from_user(kbuf, buf, count))
+	kbuf = memdup_user_nul(buf, count);
+	if (IS_ERR(kbuf)) {
+		ret = PTR_ERR(kbuf);
+		kbuf = NULL;
 		goto out;
-	kbuf[count] = '\0';
+	}
 
 	/* Parse the user data */
 	ret = -EINVAL;
@@ -756,8 +750,7 @@
 	ret = count;
 out:
 	mutex_unlock(&userns_state_mutex);
-	if (page)
-		free_page(page);
+	kfree(kbuf);
 	return ret;
 }