[PATCH v3 2/2] platform/x86: thinklmi: improved DMI handling

[Mark Pearson <mpearson-lenovo@squebb.ca>]

Fix issues reported by kernel test robot.
 - Require DMI for think-lmi.
 - Check return from getting serial string

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202506062319.F0IpDxF6-lkp@intel.com/

Signed-off-by: Mark Pearson <mpearson-lenovo@squebb.ca>
---
 - New patch added to series.

 drivers/platform/x86/lenovo/Kconfig     | 1 +
 drivers/platform/x86/lenovo/think-lmi.c | 8 +++++---
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/x86/lenovo/Kconfig b/drivers/platform/x86/lenovo/Kconfig
index a4b565283768..207dd7f88ed0 100644
--- a/drivers/platform/x86/lenovo/Kconfig
+++ b/drivers/platform/x86/lenovo/Kconfig
@@ -197,6 +197,7 @@ config THINKPAD_ACPI_HOTKEY_POLL
 config THINKPAD_LMI
 	tristate "Lenovo WMI-based systems management driver"
 	depends on ACPI_WMI
+	depends on DMI
 	select FW_ATTR_CLASS
 	help
 	  This driver allows changing BIOS settings on Lenovo machines whose
diff --git a/drivers/platform/x86/lenovo/think-lmi.c b/drivers/platform/x86/lenovo/think-lmi.c
index 143d9fdedb65..8f70c60f791f 100644
--- a/drivers/platform/x86/lenovo/think-lmi.c
+++ b/drivers/platform/x86/lenovo/think-lmi.c
@@ -772,6 +772,7 @@ static ssize_t certificate_store(struct kobject *kobj,
 	struct tlmi_pwd_setting *setting = to_tlmi_pwd_setting(kobj);
 	enum cert_install_mode install_mode = TLMI_CERT_INSTALL;
 	char *auth_str, *new_cert;
+	const char *serial;
 	char *signature;
 	char *guid;
 	int ret;
@@ -789,9 +790,10 @@ static ssize_t certificate_store(struct kobject *kobj,
 			return -EACCES;
 
 		/* Format: 'serial#, signature' */
-		auth_str = cert_command(setting,
-					dmi_get_system_info(DMI_PRODUCT_SERIAL),
-					setting->signature);
+		serial = dmi_get_system_info(DMI_PRODUCT_SERIAL);
+		if (!serial)
+			return -EINVAL;
+		auth_str = cert_command(setting, serial, setting->signature);
 		if (!auth_str)
 			return -ENOMEM;
 
-- 
2.43.0