lockdown: Restrict /dev/{mem,kmem,port} when the kernel is locked down
Allowing users to read and write to core kernel memory makes it possible for the kernel to be subverted, avoiding module loading restrictions, and also to steal cryptographic information. Disallow /dev/mem and /dev/kmem from being opened this when the kernel has been locked down to prevent this. Also disallow /dev/port from being opened to prevent raw ioport access and thus DMA from being used to accomplish the same thing. Signed-off-by:David Howells <dhowells@redhat.com> Signed-off-by:
Matthew Garrett <mjg59@google.com> Reviewed-by:
Kees Cook <keescook@chromium.org> Cc: x86@kernel.org Signed-off-by:
James Morris <jmorris@namei.org>
parent
49fcf732
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