Gentoo Archives: gentoo-user

From: Mike Gilbert <floppym@g.o>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] User eix-sync permissions problem
Date: Tue, 11 Feb 2014 02:50:38
Message-Id: CAJ0EP40uE2u=APNJB+TB3v6Tdx1usprKfCuGFQ6FDgB6rDUW2g@mail.gmail.com
In Reply to: Re: [gentoo-user] User eix-sync permissions problem by Walter Dnes
1 On Mon, Feb 10, 2014 at 8:23 PM, Walter Dnes <waltdnes@××××××××.org> wrote:
2 > On Tue, Feb 11, 2014 at 12:28:43AM +0000, Kerin Millar wrote
3 >> On 10/02/2014 23:57, Walter Dnes wrote:
4 >> >
5 >> > What's the point, if you still have to run as root (or su or sudo) for
6 >> > the emerge update process?
7 >>
8 >> It's the principle of least privilege. Is there any specific reason for
9 >> portage to fork and exec rsync as root? Is rsync sandboxed? Should rsync
10 >> have unfettered read/write access to all mounted filesystems? Can it be
11 >> guaranteed that rsync hasn't been compromised? Can it be guaranteed that
12 >> PORTAGE_RSYNC_OPTS will contain safe options at all times?
13 >>
14 >> The answer to all of these questions is "no". Basically, the combination
15 >> of usersync and non-root ownership of PORTDIR hardens the process in a
16 >> sensible way while conferring no disadvantage.
17 >
18 > If /usr/portage is owned by portage:portage, then wouldn't a user
19 > (member of portage) be able to do mischief by tweaking ebuilds? E.g.
20 > modify an ebuild to point to a tarball located on a usb stick, at
21 > http://127.0.0.1/media/sdc1/my_tarball.tgz. This would allow a local
22 > user to supply code that gets built and then installed in /usr/bin, or
23 > /sbin, etc.
24 >
25
26 Don't add untrusted users to the portage group.