From: Tyler Hicks <tyhicks@linux.microsoft.com>
To: Mimi Zohar <zohar@linux.ibm.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
Subject: [PATCH v2 04/11] ima: Fail rule parsing when buffer hook functions have an invalid action
Date: Fri, 26 Jun 2020 17:38:53 -0500 [thread overview]
Message-ID: <20200626223900.253615-5-tyhicks@linux.microsoft.com> (raw)
In-Reply-To: <20200626223900.253615-1-tyhicks@linux.microsoft.com>
Buffer based hook functions, such as KEXEC_CMDLINE and KEY_CHECK, can
only measure. The process_buffer_measurement() function quietly ignores
all actions except measure so make this behavior clear at the time of
policy load.
The parsing of the keyrings conditional had a check to ensure that it
was only specified with measure actions but the check should be on the
hook function and not the keyrings conditional since
"appraise func=KEY_CHECK" is not a valid rule.
Fixes: b0935123a183 ("IMA: Define a new hook to measure the kexec boot command line arguments")
Fixes: 5808611cccb2 ("IMA: Add KEY_CHECK func to measure keys")
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
---
* v2
- No change
security/integrity/ima/ima_policy.c | 36 +++++++++++++++++++++++++++--
1 file changed, 34 insertions(+), 2 deletions(-)
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index e458cd47c099..166124d67774 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -973,6 +973,39 @@ static void check_template_modsig(const struct ima_template_desc *template)
#undef MSG
}
+static bool ima_validate_rule(struct ima_rule_entry *entry)
+{
+ if (entry->action == UNKNOWN)
+ return false;
+
+ if (entry->flags & IMA_FUNC) {
+ switch (entry->func) {
+ case NONE:
+ case FILE_CHECK:
+ case MMAP_CHECK:
+ case BPRM_CHECK:
+ case CREDS_CHECK:
+ case POST_SETATTR:
+ case MODULE_CHECK:
+ case FIRMWARE_CHECK:
+ case KEXEC_KERNEL_CHECK:
+ case KEXEC_INITRAMFS_CHECK:
+ case POLICY_CHECK:
+ break;
+ case KEXEC_CMDLINE:
+ case KEY_CHECK:
+ if (entry->action & ~(MEASURE | DONT_MEASURE))
+ return false;
+
+ break;
+ default:
+ return false;
+ }
+ }
+
+ return true;
+}
+
static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
{
struct audit_buffer *ab;
@@ -1150,7 +1183,6 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
keyrings_len = strlen(args[0].from) + 1;
if ((entry->keyrings) ||
- (entry->action != MEASURE) ||
(entry->func != KEY_CHECK) ||
(keyrings_len < 2)) {
result = -EINVAL;
@@ -1356,7 +1388,7 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
break;
}
}
- if (!result && (entry->action == UNKNOWN))
+ if (!result && !ima_validate_rule(entry))
result = -EINVAL;
else if (entry->action == APPRAISE)
temp_ima_appraise |= ima_appraise_flag(entry->func);
--
2.25.1
next prev parent reply other threads:[~2020-06-26 22:40 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-26 22:38 [PATCH v2 00/11] ima: Fix rule parsing bugs and extend KEXEC_CMDLINE rule support Tyler Hicks
2020-06-26 22:38 ` [PATCH v2 01/11] ima: Have the LSM free its audit rule Tyler Hicks
2020-06-26 22:38 ` [PATCH v2 02/11] ima: Free the entire rule when deleting a list of rules Tyler Hicks
2020-06-26 22:38 ` [PATCH v2 03/11] ima: Free the entire rule if it fails to parse Tyler Hicks
2020-06-26 22:38 ` Tyler Hicks [this message]
2020-06-26 22:38 ` [PATCH v2 05/11] ima: Fail rule parsing when the KEXEC_CMDLINE hook is combined with an invalid cond Tyler Hicks
2020-06-27 23:40 ` Lakshmi Ramasubramanian
2020-06-26 22:38 ` [PATCH v2 06/11] ima: Fail rule parsing when the KEY_CHECK " Tyler Hicks
2020-06-27 23:39 ` Lakshmi Ramasubramanian
2020-06-26 22:38 ` [PATCH v2 07/11] ima: Shallow copy the args_p member of ima_rule_entry.lsm elements Tyler Hicks
2020-06-26 22:38 ` [PATCH v2 08/11] ima: Use correct type for " Tyler Hicks
2020-06-26 22:38 ` [PATCH v2 09/11] ima: Move validation of the keyrings conditional into ima_validate_rule() Tyler Hicks
2020-06-27 23:49 ` Lakshmi Ramasubramanian
2020-06-29 14:16 ` Tyler Hicks
2020-06-30 23:07 ` Mimi Zohar
2020-07-02 22:16 ` Tyler Hicks
2020-07-03 14:15 ` Mimi Zohar
2020-07-06 13:18 ` Tyler Hicks
2020-07-07 3:18 ` Mimi Zohar
2020-06-26 22:38 ` [PATCH v2 10/11] ima: Use the common function to detect LSM conditionals in a rule Tyler Hicks
2020-06-26 22:39 ` [PATCH v2 11/11] ima: Support additional conditionals in the KEXEC_CMDLINE hook function Tyler Hicks
2020-06-28 0:03 ` Lakshmi Ramasubramanian
2020-07-01 8:04 ` Dave Young
2020-07-01 14:38 ` Tyler Hicks
2020-07-01 0:29 ` [PATCH v2 00/11] ima: Fix rule parsing bugs and extend KEXEC_CMDLINE rule support Mimi Zohar
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=20200626223900.253615-5-tyhicks@linux.microsoft.com \
--to=tyhicks@linux.microsoft.com \
--cc=dmitry.kasatkin@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=prsriva02@gmail.com \
--cc=serge@hallyn.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).