diff options
| author | Eric Snowberg <eric.snowberg@oracle.com> | 2023-07-26 17:17:25 -0400 |
|---|---|---|
| committer | Mimi Zohar <zohar@linux.ibm.com> | 2023-08-01 08:17:25 -0400 |
| commit | f20765fdfdc2c8f47b41cb08489fdad3194a8465 (patch) | |
| tree | db736627195e31a4a667ca0012db554f1aa20adb /security/integrity/ima/ima_policy.c | |
| parent | 5087fd9e80e539d2163accd045b73da64de7de95 (diff) | |
integrity: Always reference the blacklist keyring with appraisal
Commit 273df864cf746 ("ima: Check against blacklisted hashes for files with
modsig") introduced an appraise_flag option for referencing the blacklist
keyring. Any matching binary found on this keyring fails signature
validation. This flag only works with module appended signatures.
An important part of a PKI infrastructure is to have the ability to do
revocation at a later time should a vulnerability be found. Expand the
revocation flag usage to all appraisal functions. The flag is now
enabled by default. Setting the flag with an IMA policy has been
deprecated. Without a revocation capability like this in place, only
authenticity can be maintained. With this change, integrity can now be
achieved with digital signature based IMA appraisal.
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
Reviewed-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Diffstat (limited to 'security/integrity/ima/ima_policy.c')
| -rw-r--r-- | security/integrity/ima/ima_policy.c | 17 |
1 files changed, 5 insertions, 12 deletions
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index c9b3bd8f1bb9..69452b79686b 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -1280,7 +1280,7 @@ static bool ima_validate_rule(struct ima_rule_entry *entry) IMA_FSNAME | IMA_GID | IMA_EGID | IMA_FGROUP | IMA_DIGSIG_REQUIRED | IMA_PERMIT_DIRECTIO | IMA_VALIDATE_ALGOS | - IMA_VERITY_REQUIRED)) + IMA_CHECK_BLACKLIST | IMA_VERITY_REQUIRED)) return false; break; @@ -1355,7 +1355,7 @@ static bool ima_validate_rule(struct ima_rule_entry *entry) /* Ensure that combinations of flags are compatible with each other */ if (entry->flags & IMA_CHECK_BLACKLIST && - !(entry->flags & IMA_MODSIG_ALLOWED)) + !(entry->flags & IMA_DIGSIG_REQUIRED)) return false; /* @@ -1803,11 +1803,11 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) if (entry->flags & IMA_VERITY_REQUIRED) result = -EINVAL; else - entry->flags |= IMA_DIGSIG_REQUIRED; + entry->flags |= IMA_DIGSIG_REQUIRED | IMA_CHECK_BLACKLIST; } else if (strcmp(args[0].from, "sigv3") == 0) { /* Only fsverity supports sigv3 for now */ if (entry->flags & IMA_VERITY_REQUIRED) - entry->flags |= IMA_DIGSIG_REQUIRED; + entry->flags |= IMA_DIGSIG_REQUIRED | IMA_CHECK_BLACKLIST; else result = -EINVAL; } else if (IS_ENABLED(CONFIG_IMA_APPRAISE_MODSIG) && @@ -1816,18 +1816,13 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) result = -EINVAL; else entry->flags |= IMA_DIGSIG_REQUIRED | - IMA_MODSIG_ALLOWED; + IMA_MODSIG_ALLOWED | IMA_CHECK_BLACKLIST; } else { result = -EINVAL; } break; case Opt_appraise_flag: ima_log_string(ab, "appraise_flag", args[0].from); - if (IS_ENABLED(CONFIG_IMA_APPRAISE_MODSIG) && - strstr(args[0].from, "blacklist")) - entry->flags |= IMA_CHECK_BLACKLIST; - else - result = -EINVAL; break; case Opt_appraise_algos: ima_log_string(ab, "appraise_algos", args[0].from); @@ -2271,8 +2266,6 @@ int ima_policy_show(struct seq_file *m, void *v) } if (entry->flags & IMA_VERITY_REQUIRED) seq_puts(m, "digest_type=verity "); - if (entry->flags & IMA_CHECK_BLACKLIST) - seq_puts(m, "appraise_flag=check_blacklist "); if (entry->flags & IMA_PERMIT_DIRECTIO) seq_puts(m, "permit_directio "); rcu_read_unlock(); |