selinux.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Ondrej Mosnacek <omosnace@redhat.com>
To: Paul Moore <paul@paul-moore.com>
Cc: SElinux list <selinux@vger.kernel.org>,
	Stephen Smalley <stephen.smalley.work@gmail.com>
Subject: Re: [PATCH v2 1/2] selinux: don't log MAC_POLICY_LOAD record on failed policy load
Date: Fri, 26 Feb 2021 15:46:06 +0100	[thread overview]
Message-ID: <CAFqZXNuBYwAT2-vLaTM8_Zng=vh+XsY_EvnzPYM4Z=PoCydZ+A@mail.gmail.com> (raw)
In-Reply-To: <CAHC9VhQLJKjY0KSC+=f4b=8d8n-m29j_9J5r_VQ_1BpSY8WD2w@mail.gmail.com>

On Thu, Feb 25, 2021 at 7:15 PM Paul Moore <paul@paul-moore.com> wrote:
>
> On Fri, Feb 12, 2021 at 1:59 PM Ondrej Mosnacek <omosnace@redhat.com> wrote:
> >
> > If sel_make_policy_nodes() fails, we should jump to 'out', not 'out1',
> > as the latter would incorrectly log an MAC_POLICY_LOAD audit record,
> > even though the policy hasn't actually been reloaded. The 'out1' jump
> > label now becomes unused and can be removed.
> >
> > Fixes: 02a52c5c8c3b ("selinux: move policy commit after updating selinuxfs")
> > Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
> > ---
> >  security/selinux/selinuxfs.c | 3 +--
> >  1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
> > index 01a7d50ed39b..340711e3dc9a 100644
> > --- a/security/selinux/selinuxfs.c
> > +++ b/security/selinux/selinuxfs.c
> > @@ -651,14 +651,13 @@ static ssize_t sel_write_load(struct file *file, const char __user *buf,
> >         length = sel_make_policy_nodes(fsi, newpolicy);
> >         if (length) {
> >                 selinux_policy_cancel(fsi->state, newpolicy);
> > -               goto out1;
> > +               goto out;
>
> This looks good, especially with AUDIT_MAC_POLICY_LOAD recording
> "res=1".  However, now that I'm looking at the error path here, we
> don't display anything if sel_make_policy_nodes() fails, do we?  If
> security_load_policy fails we at least do a printk(), but if this
> fails it silently kills the policy load; at the very least I think we
> want a `pr_warn_ratelimited("SELinux: failed to load policy due to
> selinuxfs failures")` or something similar.

There are error messages in some error paths in
sel_make_policy_nodes(), but not all. Those are pr_err()s, while in
sel_write_load() there is a pr_warn_ratelimited(). Could we just unify
the sel_make_policy_nodes() failure to a single message? (I don't
think the information on which part has failed is very useful as the
most likely cause here is a memory allocation failure, not bad
policy.) If so, should it be a pr_warn() or pr_err()? Ratelimited or
not?

>
> >         }
> >
> >         selinux_policy_commit(fsi->state, newpolicy);
> >
> >         length = count;
> >
> > -out1:
> >         audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
> >                 "auid=%u ses=%u lsm=selinux res=1",
> >                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
> > --
> > 2.29.2
>
> --
> paul moore
> www.paul-moore.com
>

-- 
Ondrej Mosnacek
Software Engineer, Linux Security - SELinux kernel
Red Hat, Inc.


  reply	other threads:[~2021-02-26 14:48 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-12 18:59 [PATCH v2 0/2] selinux: policy load fixes Ondrej Mosnacek
2021-02-12 18:59 ` [PATCH v2 1/2] selinux: don't log MAC_POLICY_LOAD record on failed policy load Ondrej Mosnacek
2021-02-25 18:14   ` Paul Moore
2021-02-26 14:46     ` Ondrej Mosnacek [this message]
2021-02-28 18:52       ` Paul Moore
2021-03-03  2:55         ` Tyler Hicks
2021-03-03  8:54           ` Ondrej Mosnacek
2021-03-18 14:48             ` Paul Moore
2021-03-18 15:12               ` Stephen Smalley
2021-02-12 18:59 ` [PATCH v2 2/2] selinux: fix variable scope issue in live sidtab conversion Ondrej Mosnacek
2021-02-25 19:20   ` Paul Moore
2021-02-26 14:47     ` Ondrej Mosnacek
2021-03-03  2:57   ` Tyler Hicks
2021-03-03  9:01     ` Ondrej Mosnacek
2021-03-18 11:22       ` Stephen Smalley
2021-03-18 11:45         ` Ondrej Mosnacek
2021-03-18 14:49           ` Paul Moore

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAFqZXNuBYwAT2-vLaTM8_Zng=vh+XsY_EvnzPYM4Z=PoCydZ+A@mail.gmail.com' \
    --to=omosnace@redhat.com \
    --cc=paul@paul-moore.com \
    --cc=selinux@vger.kernel.org \
    --cc=stephen.smalley.work@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).