[PATCH 5.15 148/262] thermal: core: Fix TZ_GET_TRIP NULL pointer dereference

[Greg Kroah-Hartman]

From: Nicolas Cavallari <nicolas.cavallari@xxxxxxxxxxxxxxxxxxxxxxx>

commit 5838a14832d447990827d85e90afe17e6fb9c175 upstream.

Do not call get_trip_hyst() from thermal_genl_cmd_tz_get_trip() if
the thermal zone does not define one.

Fixes: 1ce50e7d408e ("thermal: core: genetlink support for events/cmd/sampling")
Signed-off-by: Nicolas Cavallari <nicolas.cavallari@xxxxxxxxxxxxxxxxxxxxxxx>
Cc: 5.10+ <stable@xxxxxxxxxxxxxxx> # 5.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/thermal/thermal_netlink.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/thermal/thermal_netlink.c
+++ b/drivers/thermal/thermal_netlink.c
@@ -418,11 +418,12 @@ static int thermal_genl_cmd_tz_get_trip(
 	for (i = 0; i < tz->trips; i++) {
 
 		enum thermal_trip_type type;
-		int temp, hyst;
+		int temp, hyst = 0;
 
 		tz->ops->get_trip_type(tz, i, &type);
 		tz->ops->get_trip_temp(tz, i, &temp);
-		tz->ops->get_trip_hyst(tz, i, &hyst);
+		if (tz->ops->get_trip_hyst)
+			tz->ops->get_trip_hyst(tz, i, &hyst);
 
 		if (nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_TRIP_ID, i) ||
 		    nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_TRIP_TYPE, type) ||