[PATCH 4.19 230/267] ima: Call ima_calc_boot_aggregate() in ima_eventdigest_init()

Greg Kroah-Hartman
2020-06-19T15:03:27Z

From: Roberto Sassu <roberto.sassu@huawei.com>

[ Upstream commit 6cc7c266e5b47d3cd2b5bb7fd3aac4e6bb2dd1d2 ]

If the template field 'd' is chosen and the digest to be added to the
measurement entry was not calculated with SHA1 or MD5, it is
recalculated with SHA1, by using the passed file descriptor. However, this
cannot be done for boot_aggregate, because there is no file descriptor.

This patch adds a call to ima_calc_boot_aggregate() in
ima_eventdigest_init(), so that the digest can be recalculated also for the
boot_aggregate entry.

Cc: stable@vger.kernel.org # 3.13.x
Fixes: 3ce1217d6cd5d ("ima: define template fields library and new helpers")
Reported-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
security/integrity/ima/ima.h | 3 ++-
security/integrity/ima/ima_crypto.c | 6 +++---
security/integrity/ima/ima_init.c | 2 +-
security/integrity/ima/ima_template_lib.c | 18 ++++++++++++++++++
4 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index e7dfd460fe1d..d12b07eb3a58 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -56,6 +56,7 @@ extern int ima_policy_flag;
extern int ima_hash_algo;
extern int ima_appraise;
extern struct tpm_chip *ima_tpm_chip;
+extern const char boot_aggregate_name[];

/* IMA event related data */
struct ima_event_data {
@@ -139,7 +140,7 @@ int ima_calc_buffer_hash(const void *buf, loff_t len,
int ima_calc_field_array_hash(struct ima_field_data *field_data,
struct ima_template_desc *desc, int num_fields,
struct ima_digest_data *hash);
-int __init ima_calc_boot_aggregate(struct ima_digest_data *hash);
+int ima_calc_boot_aggregate(struct ima_digest_data *hash);
void ima_add_violation(struct file *file, const unsigned char *filename,
struct integrity_iint_cache *iint,
const char *op, const char *cause);
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 6a6d19ada66a..c5dd05ace28c 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -663,8 +663,8 @@ static void __init ima_pcrread(int idx, u8 *pcr)
/*
* Calculate the boot aggregate hash
*/
-static int __init ima_calc_boot_aggregate_tfm(char *digest,
- struct crypto_shash *tfm)
+static int ima_calc_boot_aggregate_tfm(char *digest,
+ struct crypto_shash *tfm)
{
u8 pcr_i[TPM_DIGEST_SIZE];
int rc, i;
@@ -688,7 +688,7 @@ static int __init ima_calc_boot_aggregate_tfm(char *digest,
return rc;
}

-int __init ima_calc_boot_aggregate(struct ima_digest_data *hash)
+int ima_calc_boot_aggregate(struct ima_digest_data *hash)
{
struct crypto_shash *tfm;
int rc;
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index faac9ecaa0ae..a2bc4cb4482a 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -25,7 +25,7 @@
#include "ima.h"

/* name for boot aggregate entry */
-static const char *boot_aggregate_name = "boot_aggregate";
+const char boot_aggregate_name[] = "boot_aggregate";
struct tpm_chip *ima_tpm_chip;

/* Add the boot aggregate to the IMA measurement list and extend
diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
index 43752002c222..48c5a1be88ac 100644
--- a/security/integrity/ima/ima_template_lib.c
+++ b/security/integrity/ima/ima_template_lib.c
@@ -284,6 +284,24 @@ int ima_eventdigest_init(struct ima_event_data *event_data,
goto out;
}

+ if ((const char *)event_data->filename == boot_aggregate_name) {
+ if (ima_tpm_chip) {
+ hash.hdr.algo = HASH_ALGO_SHA1;
+ result = ima_calc_boot_aggregate(&hash.hdr);
+
+ /* algo can change depending on available PCR banks */
+ if (!result && hash.hdr.algo != HASH_ALGO_SHA1)
+ result = -EINVAL;
+
+ if (result < 0)
+ memset(&hash, 0, sizeof(hash));
+ }
+
+ cur_digest = hash.hdr.digest;
+ cur_digestsize = hash_digest_size[HASH_ALGO_SHA1];
+ goto out;
+ }
+
if (!event_data->file) /* missing info to re-calculate the digest */
return -EINVAL;

--
2.25.1