thermal: core: prevent potential string overflow

[ Upstream commit c996260 ]

The dev->id value comes from ida_alloc() so it's a number between zero
and INT_MAX.  If it's too high then these sprintf()s will overflow.

Fixes: 203d3d4 ("the generic thermal sysfs driver")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/thermal/thermal_core.c

@@ -737,7 +737,8 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
 	if (result)
 		goto release_ida;
 
-	sprintf(dev->attr_name, "cdev%d_trip_point", dev->id);
+	snprintf(dev->attr_name, sizeof(dev->attr_name), "cdev%d_trip_point",
+		 dev->id);
 	sysfs_attr_init(&dev->attr.attr);
 	dev->attr.attr.name = dev->attr_name;
 	dev->attr.attr.mode = 0444;
@@ -746,7 +747,8 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
 	if (result)
 		goto remove_symbol_link;
 
-	sprintf(dev->weight_attr_name, "cdev%d_weight", dev->id);
+	snprintf(dev->weight_attr_name, sizeof(dev->weight_attr_name),
+		 "cdev%d_weight", dev->id);
 	sysfs_attr_init(&dev->weight_attr.attr);
 	dev->weight_attr.attr.name = dev->weight_attr_name;
 	dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;