efi: Move some sysfs files to be read-only by root
Thanks to the scripts/leaking_addresses.pl script, it was found that
some EFI values should not be readable by non-root users.
So make them root-only, and to do that, add a __ATTR_RO_MODE() macro to
make this easier, and use it in other places at the same time.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Cc: stable <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20171206095010.24170-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index e32dfe0..40839c0 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -117,6 +117,12 @@ struct attribute_group {
.show = _name##_show, \
}
+#define __ATTR_RO_MODE(_name, _mode) { \
+ .attr = { .name = __stringify(_name), \
+ .mode = VERIFY_OCTAL_PERMISSIONS(_mode) }, \
+ .show = _name##_show, \
+}
+
#define __ATTR_WO(_name) { \
.attr = { .name = __stringify(_name), .mode = S_IWUSR }, \
.store = _name##_store, \