From: Arnd Bergmann <arnd@xxxxxxxx> When CONFIG_DMI is disabled, dmi_get_system_info() returns a NULL pointer, which is now caught by a warning: In function 'strlen', inlined from 'acpi_add.part.0' at drivers/platform/x86/lg-laptop.c:658:6: include/linux/fortify-string.h:25:33: error: argument 1 null where non-null expected [-Werror=nonnull] 25 | #define __underlying_strlen __builtin_strlen | ^ include/linux/fortify-string.h:60:24: note: in expansion of macro '__underlying_strlen' 60 | return __underlying_strlen(p); | ^~~~~~~~~~~~~~~~~~~ drivers/platform/x86/lg-laptop.c: In function 'acpi_add.part.0': include/linux/fortify-string.h:25:33: note: in a call to built-in function '__builtin_strlen' 25 | #define __underlying_strlen __builtin_strlen | ^ include/linux/fortify-string.h:60:24: note: in expansion of macro '__underlying_strlen' 60 | return __underlying_strlen(p); | ^~~~~~~~~~~~~~~~~~~ The code in there does not appear essential, so an explicit NULL check should be sufficient. The string is also printed to the console, but printk() is able to handle NULL pointer arguments gracefully. Fixes: 8983bfd58d61 ("platform/x86: lg-laptop: Support for battery charge limit on newer models") Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- drivers/platform/x86/lg-laptop.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/platform/x86/lg-laptop.c b/drivers/platform/x86/lg-laptop.c index 3e520d5bca07..88b551caeaaf 100644 --- a/drivers/platform/x86/lg-laptop.c +++ b/drivers/platform/x86/lg-laptop.c @@ -655,7 +655,7 @@ static int acpi_add(struct acpi_device *device) goto out_platform_registered; } product = dmi_get_system_info(DMI_PRODUCT_NAME); - if (strlen(product) > 4) + if (product && strlen(product) > 4) switch (product[4]) { case '5': case '6': -- 2.29.2