acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down
This option allows userspace to pass the RSDP address to the kernel, which makes it possible for a user to modify the workings of hardware. Reject the option when the kernel is locked down. This requires some reworking of the existing RSDP command line logic, since the early boot code also makes use of a command-line passed RSDP when locating the SRAT table before the lockdown code has been initialised. This is achieved by separating the command line RSDP path in the early boot code from the generic RSDP path, and then copying the command line RSDP into boot params in the kernel proper if lockdown is not enabled. If lockdown is enabled and an RSDP is provided on the command line, this will only be used when parsing SRAT (which shouldn't permit kernel code execution) and will be ignored in the rest of the kernel. (Modified by Matthew Garrett in order to handle the early boot RSDP environment) Signed-off-by:Josh Boyer <jwboyer@redhat.com> Signed-off-by:
David Howells <dhowells@redhat.com> Signed-off-by:
Matthew Garrett <mjg59@google.com> Reviewed-by:
Kees Cook <keescook@chromium.org> cc: Dave Young <dyoung@redhat.com> cc: linux-acpi@vger.kernel.org Signed-off-by:
James Morris <jmorris@namei.org>
parent
f474e148
Please register or sign in to comment