From: Ricardo Branco <rbranco@suse.de>
Subject: Re: ext2fs: Drop EXT2FS_SYSTEM_FLAGS and make its behaviour the default
To: Jan Stary <hans@stare.cz>
Cc: tech@openbsd.org
Date: Mon, 29 Jan 2024 22:25:00 +0100


On 1/29/24 22:15, Jan Stary wrote:
> On Jan 29 19:50:40,rbranco@suse.de  wrote:
>> 1. When the user sets those flags, he cannot unset them later when running
>> on Linux, FreeBSD (and perhaps other systems).  Only root.
> On OpenBSD, the user can unset them too.

And _that_ is a problem.  Because you're mapping UF_IMMUTABLE and 
SF_IMMUTABLE to EXT2_IMMUTABLE_FL, if root sets the system immutable 
flag, the user can unset it after the filesystem is mounted again.

If that's not obvious, I rest my case.