Re: [gentoo-user] Re: Root can't write to files owned by others?

[Michael]

On Thursday, 10 March 2022 17:59:00 GMT Laurence Perkins wrote:
> >-----Original Message-----
> >From: Dr Rainer Woitok <rainer.woitok@×××××.com>
> >Sent: Thursday, March 10, 2022 9:51 AM
> >To: gentoo-user@l.g.o; Nikos Chantziaras <realnc@×××××.com>
> >Subject: [gentoo-user] Re: Root can't write to files owned by others?
> >
> >Nikos,
> >
> >On Thursday, 2022-03-10 12:21:36 +0200, you wrote:
> >> ...
> >> Are you sure that:
> >>
> >> sysctl fs.protected_regular=0
> >>
> >> does not help? I can reproduce it here on my system with kernel
> >> 5.15.27, and setting that sysctl to 0 fixes it immediately.
> >
> >No,  I'm not at all sure.   Since you mentioned  in your first mail that
> >this is normal  when using  "systemd",  I did not pursue  this route any
> >further, because I'm using "openrc".
> >
> >I'll search the web for "fs.protected_regular"  to get a feeling for the
> >consequences and then perhaps set this when I'll again boot kernel vers-
> >ion 5.15.26.
> >
> >Thanks for being persistent :-)
> >
> >Sincerely,
> >
> >  Rainer
>
> Basically the idea is to keep other users from being able to trick root into
> writing sensitive data to something they control. It's a "systemd thing"
> because, apparently, the systemd developers decided to have systemd enable
> it instead of leaving it in the bailiwick of the distros' configurations.
> But if the default setting changed in a later kernel as well, that would
> potentially affect everyone, so a quick check of what it's set to wouldn't
> be amiss.
>
> LMP

Just checked and it is so, on openrc:

~ # uname -r
5.15.26-gentoo
~ # sysctl -a | grep fs.protected_regular
fs.protected_regular = 1