diff --git a/drivers/char/random.c b/drivers/char/random.c
index 1a4e3ee498c7..3b14ae9152fe 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1655,22 +1655,25 @@ const struct file_operations urandom_fops = {
 static int sysctl_random_min_urandom_seed = 60;
 static int sysctl_random_write_wakeup_bits = POOL_MIN_BITS;
 static int sysctl_poolsize = POOL_BITS;
-static char sysctl_bootid[16];
+static u8 sysctl_bootid[UUID_SIZE];
 
 /*
  * This function is used to return both the bootid UUID, and random
- * UUID.  The difference is in whether table->data is NULL; if it is,
+ * UUID. The difference is in whether table->data is NULL; if it is,
  * then a new UUID is generated and returned to the user.
- *
- * If the user accesses this via the proc interface, the UUID will be
- * returned as an ASCII string in the standard UUID format; if via the
- * sysctl system call, as 16 bytes of binary data.
  */
 static int proc_do_uuid(struct ctl_table *table, int write,
 			void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-	struct ctl_table fake_table;
-	unsigned char buf[64], tmp_uuid[16], *uuid;
+	u8 tmp_uuid[UUID_SIZE], *uuid;
+	char uuid_string[UUID_STRING_LEN + 1];
+	struct ctl_table fake_table = {
+		.data = uuid_string,
+		.maxlen = UUID_STRING_LEN
+	};
+
+	if (write)
+		return -EPERM;
 
 	uuid = table->data;
 	if (!uuid) {
@@ -1685,12 +1688,8 @@ static int proc_do_uuid(struct ctl_table *table, int write,
 		spin_unlock(&bootid_spinlock);
 	}
 
-	sprintf(buf, "%pU", uuid);
-
-	fake_table.data = buf;
-	fake_table.maxlen = sizeof(buf);
-
-	return proc_dostring(&fake_table, write, buffer, lenp, ppos);
+	snprintf(uuid_string, sizeof(uuid_string), "%pU", uuid);
+	return proc_dostring(&fake_table, 0, buffer, lenp, ppos);
 }
 
 extern struct ctl_table random_table[];
@@ -1726,13 +1725,11 @@ struct ctl_table random_table[] = {
 	{
 		.procname	= "boot_id",
 		.data		= &sysctl_bootid,
-		.maxlen		= 16,
 		.mode		= 0444,
 		.proc_handler	= proc_do_uuid,
 	},
 	{
 		.procname	= "uuid",
-		.maxlen		= 16,
 		.mode		= 0444,
 		.proc_handler	= proc_do_uuid,
 	},
diff --git a/include/linux/uuid.h b/include/linux/uuid.h
index 2d095fc60204..c77fb14868b7 100644
--- a/include/linux/uuid.h
+++ b/include/linux/uuid.h
@@ -23,6 +23,7 @@
  * not including trailing NUL.
  */
 #define	UUID_STRING_LEN		36
+#define	UUID_SIZE		16
 
 static inline int uuid_le_cmp(const uuid_le u1, const uuid_le u2)
 {