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,
paul@paul-moore.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 3/3] IMA: add support to measure duplicate buffer for critical data hook
Date: Tue, 9 Feb 2021 10:31:43 -0800 [thread overview]
Message-ID: <8af5bf67-54d3-f358-6cb6-34733fc72df2@linux.microsoft.com> (raw)
In-Reply-To: <158dc2d3398316edefbafdb1cfea5eca840a06e6.camel@linux.ibm.com>
On 2021-02-08 12:24 p.m., Mimi Zohar wrote:
> Hi Tushar,
>
> On Fri, 2021-01-29 at 16:45 -0800, Tushar Sugandhi wrote:
>
>> diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c
>>
>> index c096ef8945c7..fbf359495fa8 100644
>> --- a/security/integrity/ima/ima_queue.c
>> +++ b/security/integrity/ima/ima_queue.c
>> @@ -158,7 +158,7 @@ static int ima_pcr_extend(struct tpm_digest *digests_arg, int pcr)
>> */
>> int ima_add_template_entry(struct ima_template_entry *entry, int violation,
>> const char *op, struct inode *inode,
>> - const unsigned char *filename)
>> + const unsigned char *filename, bool allow_dup)
>> {
>> u8 *digest = entry->digests[ima_hash_algo_idx].digest;
>>
> struct tpm_digestate_entry(struct ima_template_entry *entry, int violation,
Not sure I understand this. Maybe a typo? Could you please explain?
>>
>> mutex_lock(&ima_extend_list_mutex);
>> if (!violation) {
>> - if (ima_lookup_digest_entry(digest, entry->pcr)) {
>> + if (!allow_dup &&
>> + ima_lookup_digest_entry(digest, entry->pcr)) {
>
> Can't this change be simplified to "if (!violation && !allow_dup)"?
>
Sure. Will do.
Earlier I wasn't sure if 'violation' would touch any other use-cases
inadvertently. That's why I localized the change as above.
But now since we are supporting other scenarios as well,
I believe "if (!violation && !allow_dup)" would be cleaner.
> Also perhaps instead of passing another variable "allow_dup" to each of
> these functions, pass a mask containing violation and allow_dup.
>
There were examples of both approaches in ima_match_policy().
- int *pcr/ima_template_desc **template_desc as an out-param;
- and various actions as flags in return int.
Earlier I couldn't decide one way or the other, so I picked the
out-param approach.
But since allow_dup is just a single bit info, returning it as a bit in
the action flag is a cleaner solution.
Will implement it with flag in the next iteration.
Thanks again for reviewing the series. Really appreciate it.
Thanks,
Tushar
>> audit_cause = "hash_exists";
>> result = -EEXIST;
>> goto out;
>
> thanks,
>
> Mimi
>
next prev parent reply other threads:[~2021-02-09 21:21 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-30 0:45 [PATCH 0/3] support for duplicate measurement of integrity critical data Tushar Sugandhi
2021-01-30 0:45 ` [PATCH 1/3] IMA: add policy condition to measure duplicate " Tushar Sugandhi
2021-02-08 20:45 ` Mimi Zohar
2021-02-09 18:26 ` Tushar Sugandhi
2021-01-30 0:45 ` [PATCH 2/3] IMA: update functions to read allow_dup policy condition Tushar Sugandhi
2021-01-30 0:45 ` [PATCH 3/3] IMA: add support to measure duplicate buffer for critical data hook Tushar Sugandhi
2021-02-08 20:24 ` Mimi Zohar
2021-02-09 18:31 ` Tushar Sugandhi [this message]
2021-02-08 20:22 ` [PATCH 0/3] support for duplicate measurement of integrity critical data Mimi Zohar
2021-02-08 21:10 ` Mimi Zohar
2021-02-09 18:23 ` Tushar Sugandhi
2021-02-09 18:53 ` Mimi Zohar
2021-02-09 20:57 ` Tushar Sugandhi
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