Commit 82aa68af authored Jul 24, 2020 by Thierry Reding Committed by Daniel Lezcano Jul 24, 2020

thermal: core: Fix thermal zone lookup by ID



When a thermal zone is looked up by an ID and no zone is found matching
that ID, the thermal_zone_get_by_id() function will return a pointer to
the thermal zone list head which isn't actually a valid thermal zone.

This can lead to a subsequent crash because a valid pointer is returned
to the called, but dereferencing that pointer as struct thermal_zone is
not safe.

Fixes: 329b064f ("thermal: core: Get thermal zone by id")
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200724170105.2705467-1-thierry.reding@gmail.com

parent 287d9595

drivers/thermal/thermal_core.c

+5 −3

Original line number	Diff line number	Diff line
		@@ -751,16 +751,18 @@ int for_each_thermal_zone(int (cb)(struct thermal_zone_device , void *),

		struct thermal_zone_device *thermal_zone_get_by_id(int id)
		{
		struct thermal_zone_device *tz = NULL;
		struct thermal_zone_device tz, match = NULL;

		mutex_lock(&thermal_list_lock);
		list_for_each_entry(tz, &thermal_tz_list, node) {
		if (tz->id == id)
		if (tz->id == id) {
		match = tz;
		break;
		}
		}
		mutex_unlock(&thermal_list_lock);

		return tz;
		return match;
		}

		void thermal_zone_device_unbind_exception(struct thermal_zone_device *tz,

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