Linux-Integrity Archive on lore.kernel.org
 help / Atom feed
From: prakhar srivastava <prsriva02@gmail.com>
To: Roberto Sassu <roberto.sassu@huawei.com>
Cc: linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
	Mimi Zohar <zohar@linux.ibm.com>,
	ebiederm@xmission.com, vgoyal@redhat.com,
	Prakhar Srivastava <prsriva@microsoft.com>
Subject: Re: [PATCH 2/3 v5] add a new template field buf to contain the buffer
Date: Fri, 17 May 2019 16:32:36 -0700
Message-ID: <CAEFn8qKgH5FMLaudqTH6W0k7NpSoWV_NHbmiVduaQPbUNF_4Lg@mail.gmail.com> (raw)
In-Reply-To: <ec8ee6f7-3a1d-6498-e009-f85e677b448a@huawei.com>

On Tue, May 14, 2019 at 6:22 AM Roberto Sassu <roberto.sassu@huawei.com> wrote:
>
> On 5/14/2019 7:07 AM, prakhar srivastava wrote:
> > On Mon, May 13, 2019 at 6:48 AM Roberto Sassu <roberto.sassu@huawei.com> wrote:
> >>
> >> On 5/11/2019 12:37 AM, Prakhar Srivastava wrote:
> >>> From: Prakhar Srivastava <prsriva02@gmail.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 template fmt will contains the buffer itself.

>
> The purpose of ima_event_data is to pass data to the init method of
> template fields. Each method takes the data it needs.
>
> If you pass event_data->buf and event_data->buf_len to
> ima_write_template_field_data() this should be fine.

Hi Roberto,
I did some testing after making the needed code changes,
the output is as expected the buf template field only contains
the buf when the ima_event_data.buf is set.

However i just want to double check if adding two new fields to
the struct ima_event_data is approach you want me to take?
Mimi any concerns?

what all tests do i need to run to confirm i am not
in-inadvertently breaking some thing else?

Thanks,
Prakhar Srivastava
>
> Roberto
>
>
> >>> +      .field_show = ima_show_template_buf},
> >>
> >> Please update Documentation/security/IMA-templates.rst
> > Will update the documentation.
> >
> > Thanks,
> > Prakhar Srivastava
> >>
> >> Thanks
> >>
> >> Roberto
>
> --
> HUAWEI TECHNOLOGIES Duesseldorf GmbH, HRB 56063
> Managing Director: Bo PENG, Jian LI, Yanli SHI

  reply index

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-10 22:37 [PATCH 0/3 v5] Kexec cmdline bufffer measure Prakhar Srivastava
2019-05-10 22:37 ` [PATCH 1/3 v5] add a new ima hook and policy to measure the cmdline Prakhar Srivastava
2019-05-13 16:56   ` Mimi Zohar
2019-05-14  4:53     ` prakhar srivastava
2019-05-14 14:36       ` Mimi Zohar
2019-05-10 22:37 ` [PATCH 2/3 v5] add a new template field buf to contain the buffer Prakhar Srivastava
2019-05-13 13:48   ` Roberto Sassu
2019-05-14  5:07     ` prakhar srivastava
2019-05-14 13:22       ` Roberto Sassu
2019-05-17 23:32         ` prakhar srivastava [this message]
2019-05-20 12:18           ` Roberto Sassu
2019-05-10 22:37 ` [PATCH 3/3 v5] call ima_kexec_cmdline from kexec_file_load path Prakhar Srivastava
2019-05-14 14:46   ` Mimi Zohar
  -- strict thread matches above, loose matches on Subject: below --
2019-05-10 22:32 [PATCH 0/3 v5] Kexec cmdline bufffer measure Prakhar Srivastava
2019-05-10 22:32 ` [PATCH 2/3 v5] add a new template field buf to contain the buffer Prakhar Srivastava

Reply instructions:

You may reply publically 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=CAEFn8qKgH5FMLaudqTH6W0k7NpSoWV_NHbmiVduaQPbUNF_4Lg@mail.gmail.com \
    --to=prsriva02@gmail.com \
    --cc=ebiederm@xmission.com \
    --cc=linux-integrity@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=prsriva@microsoft.com \
    --cc=roberto.sassu@huawei.com \
    --cc=vgoyal@redhat.com \
    --cc=zohar@linux.ibm.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

Linux-Integrity Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-integrity/0 linux-integrity/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-integrity linux-integrity/ https://lore.kernel.org/linux-integrity \
		linux-integrity@vger.kernel.org linux-integrity@archiver.kernel.org
	public-inbox-index linux-integrity


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-integrity


AGPL code for this site: git clone https://public-inbox.org/ public-inbox