Hi, On Fri, Jul 02, 2021 at 05:08:09PM +0000, Alexander Lobakin wrote: > > On the other hand, it leaves a potentional window for attackers to > perform brute force from xattr-incapable filesystems. So at the end > of the day I think that the current implementation (a strong > rejection of such filesystems) is way more secure than having > a fallback I proposed. I've been thinking more about this: that the Brute LSM depends on xattr support and I don't like this part. I want that brute force attacks can be detected and mitigated on every system (with minimal dependencies). So, now I am working in a solution without this drawback. I have some ideas but I need to work on it. > I'm planning to make a patch which will eliminate such weird rootfs > type selection and just always use more feature-rich tmpfs if it's > compiled in. So, as an alternative, you could add it to your series > as a preparatory change and just add a Kconfig dependency on > CONFIG_TMPFS && CONFIG_TMPFS_XATTR to CONFIG_SECURITY_FORK_BRUTE > without messing with any fallbacks at all. > What do you think? Great. But I hope this patch will not be necessary for Brute LSM :) Thanks, John Wood
