On Tue, Jul 05, 2022 at 03:00:02PM +0000, Varad Gautam wrote:
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@google.com Cc: stable@vger.kernel.org
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);
Why doesn't set_cur_state() check the max state before setting it? Why are the callers forced to always check it before? That feels wrong...
thanks,
greg k-h