[PATCH] firmware: arm_scmi: use strlcpy to ensure NULL-terminated strings

[Sudeep Holla]

Replace all the memcpy() for copying name strings from the firmware with
strlcpy() to make sure we are bounded by the source buffer size and we
also always have NULL-terminated strings.

This is needed to avoid out of bounds accesses if the firmware returns
a non-terminated string.

Reported-by: Olof Johansson <olof@xxxxxxxxx>
Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
---
 drivers/firmware/arm_scmi/base.c    | 2 +-
 drivers/firmware/arm_scmi/clock.c   | 2 +-
 drivers/firmware/arm_scmi/perf.c    | 2 +-
 drivers/firmware/arm_scmi/power.c   | 2 +-
 drivers/firmware/arm_scmi/sensors.c | 2 +-
 5 files changed, 5 insertions(+), 5 deletions(-)

Hi Olof,

Let me know if this is rc/fix material or need to wait for v4.20 ?

Regards,
Sudeep

diff --git a/drivers/firmware/arm_scmi/base.c b/drivers/firmware/arm_scmi/base.c
index 9dff33ea6416..204390297f4b 100644
--- a/drivers/firmware/arm_scmi/base.c
+++ b/drivers/firmware/arm_scmi/base.c
@@ -208,7 +208,7 @@ static int scmi_base_discover_agent_get(const struct scmi_handle *handle,

 	ret = scmi_do_xfer(handle, t);
 	if (!ret)
-		memcpy(name, t->rx.buf, SCMI_MAX_STR_SIZE);
+		strlcpy(name, t->rx.buf, SCMI_MAX_STR_SIZE);

 	scmi_xfer_put(handle, t);

diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
index e4119eb34986..30fc04e28431 100644
--- a/drivers/firmware/arm_scmi/clock.c
+++ b/drivers/firmware/arm_scmi/clock.c
@@ -111,7 +111,7 @@ static int scmi_clock_attributes_get(const struct scmi_handle *handle,

 	ret = scmi_do_xfer(handle, t);
 	if (!ret)
-		memcpy(clk->name, attr->name, SCMI_MAX_STR_SIZE);
+		strlcpy(clk->name, attr->name, SCMI_MAX_STR_SIZE);
 	else
 		clk->name[0] = '\0';

diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c
index 721e6c57beae..c3b0041defee 100644
--- a/drivers/firmware/arm_scmi/perf.c
+++ b/drivers/firmware/arm_scmi/perf.c
@@ -168,7 +168,7 @@ scmi_perf_domain_attributes_get(const struct scmi_handle *handle, u32 domain,
 					le32_to_cpu(attr->sustained_perf_level);
 		dom_info->mult_factor =	(dom_info->sustained_freq_khz * 1000) /
 					dom_info->sustained_perf_level;
-		memcpy(dom_info->name, attr->name, SCMI_MAX_STR_SIZE);
+		strlcpy(dom_info->name, attr->name, SCMI_MAX_STR_SIZE);
 	}

 	scmi_xfer_put(handle, t);
diff --git a/drivers/firmware/arm_scmi/power.c b/drivers/firmware/arm_scmi/power.c
index cfa033b05aed..62f3401a1f01 100644
--- a/drivers/firmware/arm_scmi/power.c
+++ b/drivers/firmware/arm_scmi/power.c
@@ -106,7 +106,7 @@ scmi_power_domain_attributes_get(const struct scmi_handle *handle, u32 domain,
 		dom_info->state_set_notify = SUPPORTS_STATE_SET_NOTIFY(flags);
 		dom_info->state_set_async = SUPPORTS_STATE_SET_ASYNC(flags);
 		dom_info->state_set_sync = SUPPORTS_STATE_SET_SYNC(flags);
-		memcpy(dom_info->name, attr->name, SCMI_MAX_STR_SIZE);
+		strlcpy(dom_info->name, attr->name, SCMI_MAX_STR_SIZE);
 	}

 	scmi_xfer_put(handle, t);
diff --git a/drivers/firmware/arm_scmi/sensors.c b/drivers/firmware/arm_scmi/sensors.c
index 27f2092b9882..b53d5cc9c9f6 100644
--- a/drivers/firmware/arm_scmi/sensors.c
+++ b/drivers/firmware/arm_scmi/sensors.c
@@ -140,7 +140,7 @@ static int scmi_sensor_description_get(const struct scmi_handle *handle,
 			s = &si->sensors[desc_index + cnt];
 			s->id = le32_to_cpu(buf->desc[cnt].id);
 			s->type = SENSOR_TYPE(attrh);
-			memcpy(s->name, buf->desc[cnt].name, SCMI_MAX_STR_SIZE);
+			strlcpy(s->name, buf->desc[cnt].name, SCMI_MAX_STR_SIZE);
 		}

 		desc_index += num_returned;
--
2.7.4