From: Tushar Sugandhi <tusharsu@linux.microsoft.com>
To: Mimi Zohar <zohar@linux.ibm.com>,
stephen.smalley.work@gmail.com, casey@schaufler-ca.com,
agk@redhat.com, snitzer@redhat.com, gmazyland@gmail.com
Cc: tyhicks@linux.microsoft.com, sashal@kernel.org,
jmorris@namei.org, nramas@linux.microsoft.com,
linux-integrity@vger.kernel.org, selinux@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org, dm-devel@redhat.com
Subject: Re: [PATCH v3 5/6] IMA: add hook to measure critical data from kernel components
Date: Fri, 11 Sep 2020 10:38:30 -0700 [thread overview]
Message-ID: <01f5ea67-447e-c1c2-9c47-49fd3f6c16ec@linux.microsoft.com> (raw)
In-Reply-To: <6c80bdad49c72fa58b5a9fb7ce2d20c8cabe1324.camel@linux.ibm.com>
On 2020-08-31 11:23 a.m., Mimi Zohar wrote:
>> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
>> index 52cbbc1f7ea2..a889bf40cb7e 100644
>> --- a/security/integrity/ima/ima_main.c
>> +++ b/security/integrity/ima/ima_main.c
>> @@ -869,6 +869,30 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size)
>> fdput(f);
>> }
>>
>> +/**
>> + * ima_measure_critical_data - measure critical data
>> + * @event_name: name for the given data
>> + * @event_data_source: name of the event data source
>> + * @buf: pointer to buffer containing data to measure
>> + * @buf_len: length of buffer(in bytes)
>> + * @measure_buf_hash: if set to true - will measure hash of the buf,
>> + * instead of buf
>> + *
>> + * Buffers can only be measured, not appraised.
>> + */
>> +int ima_measure_critical_data(const char *event_name,
>> + const char *event_data_source,
>> + const void *buf, int buf_len,
>> + bool measure_buf_hash)
>> +{
>> + if (!event_name || !event_data_source || !buf || !buf_len)
>> + return -EINVAL;
>> +
>> + return process_buffer_measurement(NULL, buf, buf_len, event_name,
>> + CRITICAL_DATA, 0, event_data_source,
>> + measure_buf_hash);
>
> This is exactly what I'm concerned about. Failure to measure data may
> be audited, but should never fail.
>
> Mimi
>
As I responded in patch 2, I can ignore the result of
process_buffer_measurement() in ima_measure_critical_data(), and make
ima_measure_critical_data() return type as "void".
But that’s the only place where the results of p_b_m() are being used.
So I might as well just revert the return type of p_b_m() to the
original "void".
>> +}
>
next prev parent reply other threads:[~2020-09-11 17:39 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-28 1:56 [PATCH v3 0/6] IMA: Infrastructure for measurement of critical kernel data Tushar Sugandhi
2020-08-28 1:56 ` [PATCH v3 1/6] IMA: generalize keyring specific measurement constructs Tushar Sugandhi
2020-08-31 11:55 ` Mimi Zohar
2020-09-11 16:19 ` Tushar Sugandhi
2020-08-28 1:57 ` [PATCH v3 2/6] IMA: change process_buffer_measurement return type from void to int Tushar Sugandhi
2020-08-31 11:36 ` Mimi Zohar
2020-09-11 16:22 ` Tushar Sugandhi
2020-08-28 1:57 ` [PATCH v3 3/6] IMA: update process_buffer_measurement to measure buffer hash Tushar Sugandhi
2020-08-31 17:02 ` Mimi Zohar
2020-09-11 16:44 ` Tushar Sugandhi
2020-08-28 1:57 ` [PATCH v3 4/6] IMA: add policy to measure critical data from kernel components Tushar Sugandhi
2020-08-31 18:15 ` Mimi Zohar
2020-09-11 17:29 ` Tushar Sugandhi
2020-08-28 1:57 ` [PATCH v3 5/6] IMA: add hook " Tushar Sugandhi
2020-08-31 18:23 ` Mimi Zohar
2020-09-11 17:38 ` Tushar Sugandhi [this message]
2020-08-28 1:57 ` [PATCH v3 6/6] IMA: validate supported kernel data sources before measurement Tushar Sugandhi
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=01f5ea67-447e-c1c2-9c47-49fd3f6c16ec@linux.microsoft.com \
--to=tusharsu@linux.microsoft.com \
--cc=agk@redhat.com \
--cc=casey@schaufler-ca.com \
--cc=dm-devel@redhat.com \
--cc=gmazyland@gmail.com \
--cc=jmorris@namei.org \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=nramas@linux.microsoft.com \
--cc=sashal@kernel.org \
--cc=selinux@vger.kernel.org \
--cc=snitzer@redhat.com \
--cc=stephen.smalley.work@gmail.com \
--cc=tyhicks@linux.microsoft.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
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).