hwmon: Do not accept invalid name attributes

hwmon name attributes must not include '-', as specified in
Documentation/hwmon/sysfs-interface. Also filter out spaces,
tabs, wildcards, and newline characters.

Tested-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
index e176a43..a26c385 100644
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -22,6 +22,7 @@
 #include <linux/gfp.h>
 #include <linux/spinlock.h>
 #include <linux/pci.h>
+#include <linux/string.h>
 
 #define HWMON_ID_PREFIX "hwmon"
 #define HWMON_ID_FORMAT HWMON_ID_PREFIX "%d"
@@ -99,6 +100,10 @@
 	struct hwmon_device *hwdev;
 	int err, id;
 
+	/* Do not accept invalid characters in hwmon name attribute */
+	if (name && (!strlen(name) || strpbrk(name, "-* \t\n")))
+		return ERR_PTR(-EINVAL);
+
 	id = ida_simple_get(&hwmon_ida, 0, 0, GFP_KERNEL);
 	if (id < 0)
 		return ERR_PTR(id);