Check that a user-provided thermal state is within the maximum
thermal states supported by a given driver before attempting to
apply it. This prevents a subsequent OOB access in
thermal_cooling_device_stats_update() while performing
state-transition accounting on drivers that do not have this check
in their set_cur_state() handle.
Signed-off-by: Varad Gautam <varadgautam@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
drivers/thermal/thermal_sysfs.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c
index 1c4aac8464a7..0c6b0223b133 100644
--- a/drivers/thermal/thermal_sysfs.c
+++ b/drivers/thermal/thermal_sysfs.c
@@ -607,7 +607,7 @@ cur_state_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct thermal_cooling_device *cdev = to_cooling_device(dev);
- unsigned long state;
+ unsigned long state, max_state;
int result;
if (sscanf(buf, "%ld\n", &state) != 1)
@@ -618,10 +618,20 @@ cur_state_store(struct device *dev, struct device_attribute *attr,
mutex_lock(&cdev->lock);
+ result = cdev->ops->get_max_state(cdev, &max_state);
+ if (result)
+ goto unlock;
+
+ if (state > max_state) {
+ result = -EINVAL;
+ goto unlock;
+ }
+
result = cdev->ops->set_cur_state(cdev, state);
if (!result)
thermal_cooling_device_stats_update(cdev, state);
+unlock:
mutex_unlock(&cdev->lock);
return result ? result : count;
}
--
2.37.0.rc0.161.g10f37bed90-goog
