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From: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
To: Petko Manolov <petkan@mip-labs.com>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>,
	"linux-security-module@vger.kernel.org"
	<linux-security-module@vger.kernel.org>,
	"Luis R. Rodriguez" <mcgrof@suse.com>,
	"kexec@lists.infradead.org" <kexec@lists.infradead.org>,
	"linux-modules@vger.kernel.org" <linux-modules@vger.kernel.org>,
	"fsdevel@vger.kernel.org" <fsdevel@vger.kernel.org>,
	David Howells <dhowells@redhat.com>,
	David Woodhouse <dwmw2@infradead.org>,
	Kees Cook <keescook@chromium.org>,
	Dmitry Torokhov <dmitry.torokhov@gmail.com>,
	Dmitry Kasatkin <dmitry.kasatkin@gmail.com>,
	Eric Biederman <ebiederm@xmission.com>,
	Rusty Russell <rusty@rustcorp.com.au>,
	"Dmitry Kasatkin" <d.kasatkin@samsung.com>
Subject: RE: [PATCH v3 20/22] ima: load policy using path
Date: Mon, 8 Feb 2016 10:45:00 +0000
Message-ID: <C2D7A727C393B644B70DF4B4DCFB60B9C8A882@lhreml507-mbx.china.huawei.com> (raw)
In-Reply-To: <20160208103505.GA7931@bender.nucleusys.com>


________________________________________
From: Petko Manolov [petkan@mip-labs.com]
Sent: Monday, February 08, 2016 12:35 PM
To: Dmitry Kasatkin
Cc: Mimi Zohar; linux-security-module@vger.kernel.org; Luis R. Rodriguez; kexec@lists.infradead.org; linux-modules@vger.kernel.org; fsdevel@vger.kernel.org; David Howells; David Woodhouse; Kees Cook; Dmitry Torokhov; Dmitry Kasatkin; Eric Biederman; Rusty Russell; Dmitry Kasatkin
Subject: Re: [PATCH v3 20/22] ima: load policy using path

On 16-02-08 09:58:16, Dmitry Kasatkin wrote:
>
> ________________________________________
> From: Petko Manolov [petkan@mip-labs.com]
> Sent: Sunday, February 07, 2016 9:59 PM
> To: Mimi Zohar
> Cc: linux-security-module@vger.kernel.org; Luis R. Rodriguez; kexec@lists.infradead.org; linux-modules@vger.kernel.org; fsdevel@vger.kernel.org; David Howells; David Woodhouse; Kees Cook; Dmitry Torokhov; Dmitry Kasatkin; Eric Biederman; Rusty Russell; Dmitry Kasatkin; Dmitry Kasatkin
> Subject: Re: [PATCH v3 20/22] ima: load policy using path
>
> On 16-02-03 14:06:28, Mimi Zohar wrote:
> > From: Dmitry Kasatkin <d.kasatkin@samsung.com>
> >
> > We currently cannot do appraisal or signature vetting of IMA policies
> > since we currently can only load IMA policies by writing the contents
> > of the policy directly in, as follows:
> >
> > cat policy-file > <securityfs>/ima/policy
> >
> > If we provide the kernel the path to the IMA policy so it can load
> > the policy itself it'd be able to later appraise or vet the file
> > signature if it has one.  This patch adds support to load the IMA
> > policy with a given path as follows:
> >
> > echo /etc/ima/ima_policy > /sys/kernel/security/ima/policy
> >
> > Changelog v3:
> > - moved kernel_read_file_from_path() to a separate patch
> > v2:
> > - after re-ordering the patches, replace calling integrity_kernel_read()
> >   to read the file with kernel_read_file_from_path() (Mimi)
> > - Patch description re-written by Luis R. Rodriguez
> >
> > Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
> > Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
> > ---
> >  include/linux/fs.h              |  1 +
> >  security/integrity/ima/ima_fs.c | 43 +++++++++++++++++++++++++++++++++++++++--
> >  2 files changed, 42 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > index d4d556e..b648e6d 100644
> > --- a/include/linux/fs.h
> > +++ b/include/linux/fs.h
> > @@ -2531,6 +2531,7 @@ enum kernel_read_file_id {
> >       READING_MODULE,
> >       READING_KEXEC_IMAGE,
> >       READING_KEXEC_INITRAMFS,
> > +     READING_POLICY,
> >       READING_MAX_ID
> >  };
> >
> > diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
> > index f355231..00ccd67 100644
> > --- a/security/integrity/ima/ima_fs.c
> > +++ b/security/integrity/ima/ima_fs.c
> > @@ -22,6 +22,7 @@
> >  #include <linux/rculist.h>
> >  #include <linux/rcupdate.h>
> >  #include <linux/parser.h>
> > +#include <linux/vmalloc.h>
> >
> >  #include "ima.h"
> >
> > @@ -258,6 +259,41 @@ static const struct file_operations ima_ascii_measurements_ops = {
> >       .release = seq_release,
> >  };
> >
> > +static ssize_t ima_read_policy(char *path)
> > +{
> > +     void *data;
> > +     char *datap;
> > +     loff_t size;
> > +     int rc, pathlen = strlen(path);
> > +
> > +     char *p;
> > +
> > +     /* remove \n */
> > +     datap = path;
> > +     strsep(&datap, "\n");
> > +
> > +     rc = kernel_read_file_from_path(path, &data, &size, 0, READING_POLICY);
> > +     if (rc < 0)
> > +             return rc;
> > +
> > +     datap = data;
> > +     while (size > 0 && (p = strsep(&datap, "\n"))) {
> > +             pr_debug("rule: %s\n", p);
> > +             rc = ima_parse_add_rule(p);
> > +             if (rc < 0)
> > +                     break;
> > +             size -= rc;
> > +     }
> > +
> > +     vfree(data);
> > +     if (rc < 0)
> > +             return rc;
> > +     else if (size)
> > +             return -EINVAL;
> > +     else
> > +             return pathlen;
> > +}
> > +
> >  static ssize_t ima_write_policy(struct file *file, const char __user *buf,
> >                               size_t datalen, loff_t *ppos)
> >  {
> > @@ -286,9 +322,12 @@ static ssize_t ima_write_policy(struct file *file, const char __user *buf,
> >       result = mutex_lock_interruptible(&ima_write_mutex);
> >       if (result < 0)
> >               goto out_free;
> > -     result = ima_parse_add_rule(data);
> > -     mutex_unlock(&ima_write_mutex);
> >
> > +     if (data[0] == '/')
>
> >It seems that if we feed relative path to ima_policy the update will fail...
>
> Yes, i think it is always a good idea to pass absolute path.

What if we at least emit a warning so people know what's wrong?


                Petko

DK: May be a good idea to print that loading policy by path or not.

  reply index

Thread overview: 77+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-03 19:06 [PATCH v3 00/22] vfs: support for a common kernel file loader Mimi Zohar
2016-02-03 19:06 ` [PATCH v3 01/22] ima: separate 'security.ima' reading functionality from collect Mimi Zohar
2016-02-03 19:06 ` [PATCH v3 02/22] ima: refactor ima_policy_show() to display "ima_hooks" rules Mimi Zohar
2016-02-07 19:45   ` Petko Manolov
2016-02-10 19:33   ` Dmitry Kasatkin
2016-02-03 19:06 ` [PATCH v3 03/22] ima: use "ima_hooks" enum as function argument Mimi Zohar
2016-02-07 19:46   ` Petko Manolov
2016-02-10 19:35   ` Dmitry Kasatkin
2016-02-03 19:06 ` [PATCH v3 04/22] firmware: simplify dev_*() print messages for generic helpers Mimi Zohar
2016-02-04 17:26   ` Kees Cook
2016-02-03 19:06 ` [PATCH v3 05/22] firmware: move completing fw into a helper Mimi Zohar
2016-02-04 17:27   ` Kees Cook
2016-02-03 19:06 ` [PATCH v3 06/22] firmware: fold successful fw read early Mimi Zohar
2016-02-04 17:36   ` Kees Cook
2016-02-04 20:26     ` Luis R. Rodriguez
2016-02-03 19:06 ` [PATCH v3 07/22] vfs: define a generic function to read a file from the kernel Mimi Zohar
2016-02-04 17:41   ` Kees Cook
2016-02-03 19:06 ` [PATCH v3 08/22] vfs: define kernel_read_file_id enumeration Mimi Zohar
2016-02-04 17:41   ` Kees Cook
2016-02-04 19:45   ` Luis R. Rodriguez
2016-02-03 19:06 ` [PATCH v3 09/22] ima: provide buffer hash calculation function Mimi Zohar
2016-02-03 19:06 ` [PATCH v3 10/22] ima: calculate the hash of a buffer using aynchronous hash(ahash) Mimi Zohar
2016-02-10 19:58   ` Dmitry Kasatkin
2016-02-03 19:06 ` [PATCH v3 11/22] ima: define a new hook to measure and appraise a file already in memory Mimi Zohar
2016-02-10 20:27   ` Dmitry Kasatkin
2016-02-03 19:06 ` [PATCH v3 12/22] vfs: define kernel_read_file_from_path Mimi Zohar
2016-02-04 17:46   ` Kees Cook
2016-02-04 19:47   ` Luis R. Rodriguez
2016-02-03 19:06 ` [PATCH v3 13/22] firmware: replace call to fw_read_file_contents() with kernel version Mimi Zohar
2016-02-04 17:56   ` Kees Cook
2016-02-04 19:51   ` Luis R. Rodriguez
2016-02-03 19:06 ` [PATCH v3 14/22] security: define kernel_read_file hook Mimi Zohar
2016-02-04 17:57   ` Kees Cook
2016-02-04 19:54   ` Luis R. Rodriguez
2016-02-11 16:54   ` Casey Schaufler
2016-02-11 19:35     ` Mimi Zohar
2016-02-03 19:06 ` [PATCH v3 15/22] vfs: define kernel_copy_file_from_fd() Mimi Zohar
2016-02-04 17:58   ` Kees Cook
2016-02-04 19:55   ` Luis R. Rodriguez
2016-02-03 19:06 ` [PATCH v3 16/22] module: replace copy_module_from_fd with kernel version Mimi Zohar
2016-02-04 18:04   ` Kees Cook
2016-02-04 19:56   ` Luis R. Rodriguez
2016-02-05  0:19     ` Mimi Zohar
2016-02-03 19:06 ` [PATCH v3 17/22] ima: remove firmware and module specific cached status info Mimi Zohar
2016-02-07 19:56   ` Petko Manolov
2016-02-10 20:18   ` Dmitry Kasatkin
2016-02-10 23:14     ` Mimi Zohar
2016-02-03 19:06 ` [PATCH v3 18/22] kexec: replace call to copy_file_from_fd() with kernel version Mimi Zohar
2016-02-04 18:05   ` Kees Cook
2016-02-04 19:57   ` Luis R. Rodriguez
2016-02-12 12:50   ` Dave Young
2016-02-03 19:06 ` [PATCH v3 19/22] ima: support for kexec image and initramfs Mimi Zohar
2016-02-07 20:10   ` Petko Manolov
2016-02-08 23:34     ` Mimi Zohar
2016-02-10 21:09   ` Dmitry Kasatkin
2016-02-10 23:21     ` Mimi Zohar
     [not found]       ` <CACE9dm8OJ1cgbKszUG-pCiEMVarUFLLWi_jewVV-JEMGAJsA-g@mail.gmail.com>
2016-02-11  2:08         ` Mimi Zohar
2016-02-11  8:47           ` Dmitry Kasatkin
2016-02-11 12:16             ` Mimi Zohar
2016-02-12 12:53   ` Dave Young
2016-02-12 13:09     ` Mimi Zohar
2016-02-03 19:06 ` [PATCH v3 20/22] ima: load policy using path Mimi Zohar
2016-02-07 19:59   ` Petko Manolov
2016-02-08  9:58     ` Dmitry Kasatkin
2016-02-08 10:35       ` Petko Manolov
2016-02-08 10:45         ` Dmitry Kasatkin [this message]
2016-02-08 21:12           ` Mimi Zohar
2016-02-09  7:47             ` Petko Manolov
2016-02-03 19:06 ` [PATCH v3 21/22] ima: measure and appraise the IMA policy itself Mimi Zohar
2016-02-07 20:01   ` Petko Manolov
2016-02-10 20:22   ` Dmitry Kasatkin
2016-02-10 23:15     ` Mimi Zohar
2016-02-03 19:06 ` [PATCH v3 22/22] ima: require signed IMA policy Mimi Zohar
2016-02-07 20:02   ` Petko Manolov
2016-02-10 20:24   ` Dmitry Kasatkin
2016-02-04 18:15 ` [PATCH v3 00/22] vfs: support for a common kernel file loader Kees Cook
2016-02-04 23:54   ` Mimi Zohar

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