linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Cyrill Gorcunov <gorcunov@gmail.com>
To: Adrian Reber <areber@redhat.com>
Cc: "Christian Brauner" <christian.brauner@ubuntu.com>,
	"Eric Biederman" <ebiederm@xmission.com>,
	"Pavel Emelyanov" <ovzxemul@gmail.com>,
	"Oleg Nesterov" <oleg@redhat.com>,
	"Dmitry Safonov" <0x7f454c46@gmail.com>,
	"Andrei Vagin" <avagin@gmail.com>,
	"Nicolas Viennot" <Nicolas.Viennot@twosigma.com>,
	"Michał Cłapiński" <mclapinski@google.com>,
	"Kamil Yurtsever" <kyurtsever@google.com>,
	"Dirk Petersen" <dipeit@gmail.com>,
	"Christine Flood" <chf@redhat.com>,
	"Casey Schaufler" <casey@schaufler-ca.com>,
	"Mike Rapoport" <rppt@linux.ibm.com>,
	"Radostin Stoyanov" <rstoyanov1@gmail.com>,
	"Serge Hallyn" <serge@hallyn.com>,
	"Stephen Smalley" <stephen.smalley.work@gmail.com>,
	"Sargun Dhillon" <sargun@sargun.me>,
	"Arnd Bergmann" <arnd@arndb.de>,
	linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org, selinux@vger.kernel.org,
	"Eric Paris" <eparis@parisplace.org>,
	"Jann Horn" <jannh@google.com>,
	linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v2 1/3] capabilities: Introduce CAP_CHECKPOINT_RESTORE
Date: Wed, 3 Jun 2020 20:01:35 +0300	[thread overview]
Message-ID: <20200603170135.GD568636@grain> (raw)
In-Reply-To: <20200603162328.854164-2-areber@redhat.com>

On Wed, Jun 03, 2020 at 06:23:26PM +0200, Adrian Reber wrote:
...
>  
>  /*
> - * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
> - * symlinks may be used to bypass permissions on ancestor directories in the
> - * path to the file in question.
> + * Only allow CAP_SYS_ADMIN and CAP_CHECKPOINT_RESTORE to follow the links, due
> + * to concerns about how the symlinks may be used to bypass permissions on
> + * ancestor directories in the path to the file in question.
>   */
>  static const char *
>  proc_map_files_get_link(struct dentry *dentry,
>  			struct inode *inode,
>  		        struct delayed_call *done)
>  {
> -	if (!capable(CAP_SYS_ADMIN))
> +	if (!(capable(CAP_SYS_ADMIN) || capable(CAP_CHECKPOINT_RESTORE)))
>  		return ERR_PTR(-EPERM);

You know, I'm still not sure if we need this capable() check at all since
we have proc_fd_access_allowed() called but anyway can we please make this
if() condition more explicit

	if (!capable(CAP_SYS_ADMIN) && !capable(CAP_CHECKPOINT_RESTORE))
		return ERR_PTR(-EPERM);

though I won't insist. And I'll reread the series a bit later once I've
some spare time to.

  reply	other threads:[~2020-06-03 17:01 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-03 16:23 [PATCH v2 0/3] capabilities: Introduce CAP_CHECKPOINT_RESTORE Adrian Reber
2020-06-03 16:23 ` [PATCH v2 1/3] " Adrian Reber
2020-06-03 17:01   ` Cyrill Gorcunov [this message]
2020-06-09  3:42   ` Andrei Vagin
2020-06-09  7:44     ` Christian Brauner
2020-06-09 16:06       ` Andrei Vagin
2020-06-09 16:14         ` Christian Brauner
2020-06-10  7:59           ` Andrei Vagin
2020-06-10 15:41             ` Casey Schaufler
2020-06-10 15:48               ` Christian Brauner
2020-06-09 18:45   ` Cyrill Gorcunov
2020-06-09 20:09     ` Nicolas Viennot
2020-06-09 21:05       ` Eric W. Biederman
2020-06-09 21:28       ` Cyrill Gorcunov
2020-06-03 16:23 ` [PATCH v2 2/3] selftests: add clone3() CAP_CHECKPOINT_RESTORE test Adrian Reber
2020-06-03 16:23 ` [PATCH v2 3/3] prctl: Allow ptrace capable processes to change exe_fd Adrian Reber

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=20200603170135.GD568636@grain \
    --to=gorcunov@gmail.com \
    --cc=0x7f454c46@gmail.com \
    --cc=Nicolas.Viennot@twosigma.com \
    --cc=areber@redhat.com \
    --cc=arnd@arndb.de \
    --cc=avagin@gmail.com \
    --cc=casey@schaufler-ca.com \
    --cc=chf@redhat.com \
    --cc=christian.brauner@ubuntu.com \
    --cc=dipeit@gmail.com \
    --cc=ebiederm@xmission.com \
    --cc=eparis@parisplace.org \
    --cc=jannh@google.com \
    --cc=kyurtsever@google.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=mclapinski@google.com \
    --cc=oleg@redhat.com \
    --cc=ovzxemul@gmail.com \
    --cc=rppt@linux.ibm.com \
    --cc=rstoyanov1@gmail.com \
    --cc=sargun@sargun.me \
    --cc=selinux@vger.kernel.org \
    --cc=serge@hallyn.com \
    --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).