linux-kernel - Re: [PATCH 2/3 v5] add a new template field buf to contain the buffer

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAEFn8qJVvNivP6Lmx+nVewPcHjH=V2OrR_HyHR6nOeuVQW0A4w@mail.gmail.com>
Date:   Mon, 13 May 2019 22:07:08 -0700
From:   prakhar srivastava <prsriva02@...il.com>
To:     Roberto Sassu <roberto.sassu@...wei.com>
Cc:     linux-integrity@...r.kernel.org,
        inux-security-module@...r.kernel.org, linux-kernel@...r.kernel.org,
        Mimi Zohar <zohar@...ux.ibm.com>, ebiederm@...ssion.com,
        vgoyal@...hat.com, Prakhar Srivastava <prsriva@...rosoft.com>
Subject: Re: [PATCH 2/3 v5] add a new template field buf to contain the buffer

On Mon, May 13, 2019 at 6:48 AM Roberto Sassu <roberto.sassu@...wei.com> wrote:
>
> On 5/11/2019 12:37 AM, Prakhar Srivastava wrote:
> > From: Prakhar Srivastava <prsriva02@...il.com>
> >
> > The buffer(cmdline args) added to the ima log cannot be attested
> > without having the actual buffer. Thus to make the measured buffer
> > available to store/read a new ima template (buf) is added.
>
> Hi Prakhar
>
> please fix the typos. More comments below.
>
>
> > +     buffer_event_data->type = IMA_XATTR_BUFFER;
> > +     buffer_event_data->buf_length = size;
> > +     memcpy(buffer_event_data->buf, buf, size);
> > +
> > +     event_data.xattr_value = (struct evm_ima_xattr_data *)buffer_event_data;
> > +     event_data.xattr_len = alloc_length;
>
> I would prefer that you introduce two new fields in the ima_event_data
> structure. You can initialize them directly with the parameters of
> process_buffer_measurement().
I will make the edits, this will definitely save the kzalloc in this code
path.
>
> ima_write_template_field_data() will make
> a copy.
>
Since event_data->type is used to distinguish what the template field
 should contain.
Removing the type and subsequent check in the template_init,
 buf template fmt will result in the whole event_Data structure
being added to the log, which is not the expected output.
For buffer entries, the buf templet fmt will contains the buffer itself.

>
> > +      .field_show = ima_show_template_buf},
>
> Please update Documentation/security/IMA-templates.rst
Will update the documentation.

Thanks,
Prakhar Srivastava
>
> Thanks
>
> Roberto