What permissions should a udev rule have for a USB device? 644? 755?

For example on Ubuntu I'm looking at this file: /etc/udev/rules.d/99-lpcscrypt.rules


There's no reason to make a udev rule executable. They aren't executable (the kernel wouldn't do anything with them) and udev doesn't attach a special meaning to executable rule files.

A udev rule must not be writable to non-root user. A user who modifies it could inject arbitrary code that is run as root.

Udev rules don't normally contain anything confidential. Pretty much any information that's there can be revealed through /sys interfaces, /dev entries, ps calls while a RUN directive is running, etc.

So the right permissions are 644.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.