From 32bc5496b48174dbca1f187f710955ee4d9527a1 Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Sun, 17 May 2026 20:02:42 +0100 Subject: [PATCH] firmware: arm_scmi: Validate SENSOR_UPDATE payload size SENSOR_UPDATE carries one or more sensor readings after the fixed notification header. The parser derives the expected reading count from the sensor description, but it did not verify that the received payload contains those entries before parsing them. Reject truncated update notifications before reading the variable array. Link: https://patch.msgid.link/20260517-scmi_fixes-v1-3-d86daec4defd@kernel.org Reviewed-by: Cristian Marussi Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/sensors.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/arm_scmi/sensors.c b/drivers/firmware/arm_scmi/sensors.c index 836c294a9f42..b14bb1146356 100644 --- a/drivers/firmware/arm_scmi/sensors.c +++ b/drivers/firmware/arm_scmi/sensors.c @@ -1072,12 +1072,15 @@ scmi_sensor_fill_custom_report(const struct scmi_protocol_handle *ph, case SCMI_EVENT_SENSOR_UPDATE: { int i; + size_t expected_sz; struct scmi_sensor_info *s; const struct scmi_sensor_update_notify_payld *p = payld; struct scmi_sensor_update_report *r = report; struct sensors_info *sinfo = ph->get_priv(ph); - /* payld_sz is variable for this event */ + if (payld_sz < sizeof(*p)) + break; + r->sensor_id = le32_to_cpu(p->sensor_id); if (r->sensor_id >= sinfo->num_sensors) break; @@ -1091,6 +1094,11 @@ scmi_sensor_fill_custom_report(const struct scmi_protocol_handle *ph, * readings defined for this sensor or 1 for scalar sensors. */ r->readings_count = s->num_axis ?: 1; + expected_sz = sizeof(*p) + r->readings_count * + sizeof(p->readings[0]); + if (payld_sz < expected_sz) + break; + for (i = 0; i < r->readings_count; i++) scmi_parse_sensor_readings(&r->readings[i], &p->readings[i]);