On Fri, Aug 25, 2023 at 10:09:51PM +0000, Justin Stitt wrote: > `strncpy` is deprecated for use on NUL-terminated destination strings [1]. > > We see that `prop->cpucp_info.card_name` is supposed to be > NUL-terminated based on its usage within `__hwmon_device_register()` > (wherein it's called "name"): > | if (name && (!strlen(name) || strpbrk(name, "-* \t\n"))) > | dev_warn(dev, > | "hwmon: '%s' is not a valid name attribute, please fix\n", > | name); > > A suitable replacement is `strscpy_pad` [2] due to the fact that it > guarantees both NUL-termination and NUL-padding on its destination > buffer. > > NUL-padding on `prop->cpucp_info.card_name` is not strictly necessary as > `hdev->prop` is explicitly zero-initialized but should be used > regardless as it gets copied out to userspace directly -- as per Kees' suggestion. > > Link: www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings[1] > Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] > Link: https://github.com/KSPP/linux/issues/90 > Cc: linux-hardening@xxxxxxxxxxxxxxx > Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx> Thanks for the consolidation and refresh. :) Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> -- Kees Cook
