From: Mimi Zohar <zohar@linux.ibm.com>
To: Tyler Hicks <tyhicks@linux.microsoft.com>,
Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: James Morris <jmorris@namei.org>,
"Serge E . Hallyn" <serge@hallyn.com>,
Lakshmi Ramasubramanian <nramas@linux.microsoft.com>,
Prakhar Srivastava <prsriva02@gmail.com>,
linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org,
linux-security-module@vger.kernel.org,
Nayna Jain <nayna@linux.ibm.com>
Subject: Re: [PATCH v3 07/12] ima: Fail rule parsing when appraise_flag=blacklist is unsupportable
Date: Thu, 16 Jul 2020 14:14:50 -0400 [thread overview]
Message-ID: <1594923290.12900.376.camel@linux.ibm.com> (raw)
In-Reply-To: <20200709061911.954326-8-tyhicks@linux.microsoft.com>
On Thu, 2020-07-09 at 01:19 -0500, Tyler Hicks wrote:
> The "appraise_flag" option is only appropriate for appraise actions
> and its "blacklist" value is only appropriate when
> CONFIG_IMA_APPRAISE_MODSIG is enabled and "appraise_flag=blacklist" is
> only appropriate when "appraise_type=imasig|modsig" is also present.
> Make this clear at policy load so that IMA policy authors don't assume
> that other uses of "appraise_flag=blacklist" are supported.
The code looks correct, but this patch description could be written at
a higher level. Perhaps it just needs to be prefixed with something
like this:
Verifying that a file hash is not blacklisted is currently only
supported for files with appended signatures (modsig). In the future,
this might change. For now, ...
Mimi
>
> Fixes: 273df864cf74 ("ima: Check against blacklisted hashes for files with modsig")
> Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
> Cc: Nayna Jain <nayna@linux.ibm.com>
> ---
>
> * v3
> - New patch
>
> security/integrity/ima/ima_policy.c | 13 ++++++++++++-
> 1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index 81da02071d41..9842e2e0bc6d 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -1035,6 +1035,11 @@ static bool ima_validate_rule(struct ima_rule_entry *entry)
> return false;
> }
>
> + /* Ensure that combinations of flags are compatible with each other */
> + if (entry->flags & IMA_CHECK_BLACKLIST &&
> + !(entry->flags & IMA_MODSIG_ALLOWED))
> + return false;
> +
> return true;
> }
>
> @@ -1371,8 +1376,14 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
> result = -EINVAL;
> break;
> case Opt_appraise_flag:
> + if (entry->action != APPRAISE) {
> + result = -EINVAL;
> + break;
> + }
> +
> ima_log_string(ab, "appraise_flag", args[0].from);
> - if (strstr(args[0].from, "blacklist"))
> + if (IS_ENABLED(CONFIG_IMA_APPRAISE_MODSIG) &&
> + strstr(args[0].from, "blacklist"))
> entry->flags |= IMA_CHECK_BLACKLIST;
> break;
> case Opt_permit_directio:
next prev parent reply other threads:[~2020-07-16 18:15 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-09 6:18 [PATCH v3 00/12] ima: Fix rule parsing bugs and extend KEXEC_CMDLINE rule support Tyler Hicks
2020-07-09 6:19 ` [PATCH v3 01/12] ima: Have the LSM free its audit rule Tyler Hicks
2020-07-17 19:20 ` Nayna
2020-07-17 19:24 ` Tyler Hicks
2020-07-19 11:02 ` Mimi Zohar
2020-07-09 6:19 ` [PATCH v3 02/12] ima: Free the entire rule when deleting a list of rules Tyler Hicks
2020-07-09 6:19 ` [PATCH v3 03/12] ima: Free the entire rule if it fails to parse Tyler Hicks
2020-07-09 6:19 ` [PATCH v3 04/12] ima: Fail rule parsing when buffer hook functions have an invalid action Tyler Hicks
2020-07-09 6:19 ` [PATCH v3 05/12] ima: Fail rule parsing when the KEXEC_CMDLINE hook is combined with an invalid cond Tyler Hicks
2020-07-09 6:19 ` [PATCH v3 06/12] ima: Fail rule parsing when the KEY_CHECK " Tyler Hicks
2020-07-17 18:56 ` Nayna
2020-07-17 19:18 ` Tyler Hicks
2020-07-17 23:39 ` Tyler Hicks
2020-07-09 6:19 ` [PATCH v3 07/12] ima: Fail rule parsing when appraise_flag=blacklist is unsupportable Tyler Hicks
2020-07-16 18:14 ` Mimi Zohar [this message]
2020-07-16 18:20 ` Tyler Hicks
[not found] ` <76d2b27b-3b59-1852-046a-b1718c62b167@linux.vnet.ibm.com>
2020-07-17 18:11 ` Tyler Hicks
2020-07-20 17:02 ` Nayna
2020-07-09 6:19 ` [PATCH v3 08/12] ima: Shallow copy the args_p member of ima_rule_entry.lsm elements Tyler Hicks
2020-07-17 15:35 ` Konsta Karsisto
2020-07-17 16:51 ` Tyler Hicks
2020-07-09 6:19 ` [PATCH v3 09/12] ima: Use correct type for " Tyler Hicks
2020-07-09 6:19 ` [PATCH v3 10/12] ima: Move comprehensive rule validation checks out of the token parser Tyler Hicks
2020-07-09 6:19 ` [PATCH v3 11/12] ima: Use the common function to detect LSM conditionals in a rule Tyler Hicks
2020-07-09 6:19 ` [PATCH v3 12/12] ima: Support additional conditionals in the KEXEC_CMDLINE hook function Tyler Hicks
2020-07-17 4:31 ` [PATCH v3 00/12] ima: Fix rule parsing bugs and extend KEXEC_CMDLINE rule support Mimi Zohar
2020-07-17 4:34 ` Tyler Hicks
2020-07-20 21:38 ` Mimi Zohar
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