Re: [devel] [PATCH hasher-priv v1 0/3] Make a daemon from the hasher-priv

[Alexey Gladkov <legion@altlinux.ru>]

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On Thu, Sep 17, 2020 at 04:09:35PM +0300, Arseny Maslennikov wrote:
> On Fri, Dec 13, 2019 at 12:42:02PM +0100, Alex Gladkov wrote:
> > From: Alexey Gladkov <legion@altlinux.org>
> > 
> > The hasher-priv is a SUID utility. This is not good. Separation of the
> > server and client parts will allow us to remove SUID flag.
> > 
> > The separation of server and client is not intended to give clients
> > access over the network. This separation is only necessary to distinguish
> > privileges. Only UNIX domain socket is used.
> > 
> > A separate session process is created for each connected user. Each such
> > process ends after a certain period of inactivity.
> 
> Thank you for trying this idea out; despite the trolling attempts, this
> effort is long welcome.

I created this patchset a long time ago. I've already lost my context. It
might be better if you keep working on this patch.

> There are some issues with the patchset, which I intend to cover in
> subsequent emails. I have published[1] some fix-up commits on top of
> these patches in an attempt to ensure that, barring the issues with a
> known fix, this works; however, some bugs are definitely still unsolved
> by now, so I decided to discuss the more apparent points first.
> 
> [1] http://git.altlinux.org/people/arseny/packages/hasher-priv.git?a=summary

It looks like you've already started working on finalizing this patch :)

> There's an issue when hasher-privd tries to fulfill a chrootuid{1,2}
> request: the (eventually) unprivileged task executor process
> successfully invokes waitpid() or the likes on a child process,
> select()s on I/O descriptors, but gets CHLD later — and it looks like
> the inherited signal handler causes it to wait again.

Hm...

> I've not yet found a decent reproducer — the following command:
> `hsh-shell $workdir'

There is no such command. You need to send command to run /bin/sh.

> reproduces the issue reliably for me, but hsh-mkchroot, hsh-rmchroot,
> hsh-install are all OK. The root cause nevertheless is not yet
> established. It looks like this has to be patched somewhere in
> chrootuid(), but I might be wrong on this one.
> 
> > 
> > Alexey Gladkov (3):
> >   Make a daemon from the hasher-priv
> >   Add systemd and sysvinit service files
> >   Add cgroup support
> > 
> >  hasher-priv/.gitignore            |   1 +
> >  hasher-priv/DESIGN                | 281 +++++++++++++--------
> >  hasher-priv/Makefile              |  34 ++-
> >  hasher-priv/caller.c              |  81 +++---
> >  hasher-priv/caller_server.c       | 373 ++++++++++++++++++++++++++++
> >  hasher-priv/caller_task.c         | 217 +++++++++++++++++
> >  hasher-priv/cgroup.c              | 119 +++++++++
> >  hasher-priv/cmdline.c             |  27 +-
> >  hasher-priv/communication.c       | 392 ++++++++++++++++++++++++++++++
> >  hasher-priv/communication.h       |  77 ++++++
> >  hasher-priv/config.c              | 148 ++++++++++-
> >  hasher-priv/epoll.c               |  39 +++
> >  hasher-priv/epoll.h               |  18 ++
> >  hasher-priv/hasher-priv.c         |  78 ++++++
> >  hasher-priv/hasher-privd.c        | 375 ++++++++++++++++++++++++++++
> >  hasher-priv/hasher-privd.service  |  11 +
> >  hasher-priv/hasher-privd.sysvinit |  86 +++++++
> >  hasher-priv/io_log.c              |   2 +-
> >  hasher-priv/io_x11.c              |   2 +-
> >  hasher-priv/killuid.c             |   2 +-
> >  hasher-priv/logging.c             |  64 +++++
> >  hasher-priv/logging.h             |  55 +++++
> >  hasher-priv/main.c                |  75 ------
> >  hasher-priv/pass.c                | 117 ++++++++-
> >  hasher-priv/pidfile.c             | 128 ++++++++++
> >  hasher-priv/pidfile.h             |  44 ++++
> >  hasher-priv/priv.h                |  35 ++-
> >  hasher-priv/server.conf           |  22 ++
> >  hasher-priv/sockets.c             | 183 ++++++++++++++
> >  hasher-priv/sockets.h             |  32 +++
> >  hasher-priv/x11.c                 |   1 +
> >  31 files changed, 2872 insertions(+), 247 deletions(-)
> >  create mode 100644 hasher-priv/caller_server.c
> >  create mode 100644 hasher-priv/caller_task.c
> >  create mode 100644 hasher-priv/cgroup.c
> >  create mode 100644 hasher-priv/communication.c
> >  create mode 100644 hasher-priv/communication.h
> >  create mode 100644 hasher-priv/epoll.c
> >  create mode 100644 hasher-priv/epoll.h
> >  create mode 100644 hasher-priv/hasher-priv.c
> >  create mode 100644 hasher-priv/hasher-privd.c
> >  create mode 100644 hasher-priv/hasher-privd.service
> >  create mode 100755 hasher-priv/hasher-privd.sysvinit
> >  create mode 100644 hasher-priv/logging.c
> >  create mode 100644 hasher-priv/logging.h
> >  delete mode 100644 hasher-priv/main.c
> >  create mode 100644 hasher-priv/pidfile.c
> >  create mode 100644 hasher-priv/pidfile.h
> >  create mode 100644 hasher-priv/server.conf
> >  create mode 100644 hasher-priv/sockets.c
> >  create mode 100644 hasher-priv/sockets.h
> > 



-- 
Rgrds, legion


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