[PATCH] greybus: firmware: use strscpy, fix tag size

[Pranav Tyagi]

Increase the size of firmware_tag arrays in the following structs from
GB_FIRMWARE_U_TAG_MAX_SIZE to GB_FIRMWARE_U_TAG_MAX_SIZE + 1 to
accommodate null termination:
	- fw_mgmt_ioc_intf_load_and_validate
	- fw_mgmt_ioc_get_backend_version
	- fw_mgmt_ioc_backend_fw_update
	- fw_mgmt_ioc_get_intf_version

Replace strncpy() with strscpy() to ensure proper null termination as
firmware_tag is interpreted as a null-terminated string
and printed with %s.

Signed-off-by: Pranav Tyagi <pranav.tyagi03@xxxxxxxxx>
---
 .../greybus/Documentation/firmware/firmware.c        | 12 ++++++------
 drivers/staging/greybus/greybus_firmware.h           |  8 ++++----
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/greybus/Documentation/firmware/firmware.c b/drivers/staging/greybus/Documentation/firmware/firmware.c
index 765d69faa9cc..3b4061f4b34a 100644
--- a/drivers/staging/greybus/Documentation/firmware/firmware.c
+++ b/drivers/staging/greybus/Documentation/firmware/firmware.c
@@ -63,8 +63,8 @@ static int update_intf_firmware(int fd)
 	intf_load.major = 0;
 	intf_load.minor = 0;
 
-	strncpy((char *)&intf_load.firmware_tag, firmware_tag,
-		GB_FIRMWARE_U_TAG_MAX_SIZE);
+	strscpy((char *)&intf_load.firmware_tag, firmware_tag,
+		GB_FIRMWARE_U_TAG_MAX_SIZE + 1);
 
 	ret = ioctl(fd, FW_MGMT_IOC_INTF_LOAD_AND_VALIDATE, &intf_load);
 	if (ret < 0) {
@@ -101,8 +101,8 @@ static int update_backend_firmware(int fd)
 	/* Get Backend Firmware Version */
 	printf("Getting Backend Firmware Version\n");
 
-	strncpy((char *)&backend_fw_info.firmware_tag, firmware_tag,
-		GB_FIRMWARE_U_TAG_MAX_SIZE);
+	strscpy((char *)&backend_fw_info.firmware_tag, firmware_tag,
+		GB_FIRMWARE_U_TAG_MAX_SIZE + 1);
 
 retry_fw_version:
 	ret = ioctl(fd, FW_MGMT_IOC_GET_BACKEND_FW, &backend_fw_info);
@@ -129,8 +129,8 @@ static int update_backend_firmware(int fd)
 	/* Try Backend Firmware Update over Unipro */
 	printf("Updating Backend Firmware\n");
 
-	strncpy((char *)&backend_update.firmware_tag, firmware_tag,
-		GB_FIRMWARE_U_TAG_MAX_SIZE);
+	strscpy((char *)&backend_update.firmware_tag, firmware_tag,
+		GB_FIRMWARE_U_TAG_MAX_SIZE + 1);
 
 retry_fw_update:
 	backend_update.status = 0;
diff --git a/drivers/staging/greybus/greybus_firmware.h b/drivers/staging/greybus/greybus_firmware.h
index b6042a82ada4..ad5b2c8a6461 100644
--- a/drivers/staging/greybus/greybus_firmware.h
+++ b/drivers/staging/greybus/greybus_firmware.h
@@ -38,20 +38,20 @@
 
 /* IOCTL support */
 struct fw_mgmt_ioc_get_intf_version {
-	__u8 firmware_tag[GB_FIRMWARE_U_TAG_MAX_SIZE];
+	__u8 firmware_tag[GB_FIRMWARE_U_TAG_MAX_SIZE + 1];
 	__u16 major;
 	__u16 minor;
 } __packed;
 
 struct fw_mgmt_ioc_get_backend_version {
-	__u8 firmware_tag[GB_FIRMWARE_U_TAG_MAX_SIZE];
+	__u8 firmware_tag[GB_FIRMWARE_U_TAG_MAX_SIZE + 1];
 	__u16 major;
 	__u16 minor;
 	__u8 status;
 } __packed;
 
 struct fw_mgmt_ioc_intf_load_and_validate {
-	__u8 firmware_tag[GB_FIRMWARE_U_TAG_MAX_SIZE];
+	__u8 firmware_tag[GB_FIRMWARE_U_TAG_MAX_SIZE + 1];
 	__u8 load_method;
 	__u8 status;
 	__u16 major;
@@ -59,7 +59,7 @@ struct fw_mgmt_ioc_intf_load_and_validate {
 } __packed;
 
 struct fw_mgmt_ioc_backend_fw_update {
-	__u8 firmware_tag[GB_FIRMWARE_U_TAG_MAX_SIZE];
+	__u8 firmware_tag[GB_FIRMWARE_U_TAG_MAX_SIZE + 1];
 	__u8 status;
 } __packed;
 
-- 
2.49.0