[PATCH 4.14 05/45] thermal: core: prevent potential string overflow

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter@linaro.org>

[ Upstream commit c99626092efca3061b387043d4a7399bf75fbdd5 ]

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: 203d3d4aa482 ("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 | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 8374b8078b7df..e24d46f715715 100644
--- a/drivers/thermal/thermal_core.c
+++ b/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;
-- 
2.42.0