diff options
Diffstat (limited to 'security')
| -rw-r--r-- | security/integrity/ima/ima.h | 6 | ||||
| -rw-r--r-- | security/integrity/ima/ima_modsig.c | 20 | ||||
| -rw-r--r-- | security/integrity/ima/ima_policy.c | 57 |
3 files changed, 37 insertions, 46 deletions
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 59ec28f5c117..ea7e77536f3c 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -372,7 +372,6 @@ static inline int ima_read_xattr(struct dentry *dentry, #endif /* CONFIG_IMA_APPRAISE */ #ifdef CONFIG_IMA_APPRAISE_MODSIG -bool ima_hook_supports_modsig(enum ima_hooks func); int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len, struct modsig **modsig); void ima_collect_modsig(struct modsig *modsig, const void *buf, loff_t size); @@ -382,11 +381,6 @@ int ima_get_raw_modsig(const struct modsig *modsig, const void **data, u32 *data_len); void ima_free_modsig(struct modsig *modsig); #else -static inline bool ima_hook_supports_modsig(enum ima_hooks func) -{ - return false; -} - static inline int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len, struct modsig **modsig) { diff --git a/security/integrity/ima/ima_modsig.c b/security/integrity/ima/ima_modsig.c index d106885cc495..fb25723c65bc 100644 --- a/security/integrity/ima/ima_modsig.c +++ b/security/integrity/ima/ima_modsig.c @@ -32,26 +32,6 @@ struct modsig { u8 raw_pkcs7[]; }; -/** - * ima_hook_supports_modsig - can the policy allow modsig for this hook? - * - * modsig is only supported by hooks using ima_post_read_file(), because only - * they preload the contents of the file in a buffer. FILE_CHECK does that in - * some cases, but not when reached from vfs_open(). POLICY_CHECK can support - * it, but it's not useful in practice because it's a text file so deny. - */ -bool ima_hook_supports_modsig(enum ima_hooks func) -{ - switch (func) { - case KEXEC_KERNEL_CHECK: - case KEXEC_INITRAMFS_CHECK: - case MODULE_CHECK: - return true; - default: - return false; - } -} - /* * ima_read_modsig - Read modsig from buf. * diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 37438bffc62b..c679144af042 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -984,10 +984,27 @@ static void check_template_modsig(const struct ima_template_desc *template) static bool ima_validate_rule(struct ima_rule_entry *entry) { - /* Ensure that the action is set */ + /* Ensure that the action is set and is compatible with the flags */ if (entry->action == UNKNOWN) return false; + if (entry->action != MEASURE && entry->flags & IMA_PCR) + return false; + + if (entry->action != APPRAISE && + entry->flags & (IMA_DIGSIG_REQUIRED | IMA_MODSIG_ALLOWED | IMA_CHECK_BLACKLIST)) + return false; + + /* + * The IMA_FUNC bit must be set if and only if there's a valid hook + * function specified, and vice versa. Enforcing this property allows + * for the NONE case below to validate a rule without an explicit hook + * function. + */ + if (((entry->flags & IMA_FUNC) && entry->func == NONE) || + (!(entry->flags & IMA_FUNC) && entry->func != NONE)) + return false; + /* * Ensure that the hook function is compatible with the other * components of the rule @@ -999,12 +1016,27 @@ static bool ima_validate_rule(struct ima_rule_entry *entry) case BPRM_CHECK: case CREDS_CHECK: case POST_SETATTR: - case MODULE_CHECK: case FIRMWARE_CHECK: + case POLICY_CHECK: + if (entry->flags & ~(IMA_FUNC | IMA_MASK | IMA_FSMAGIC | + IMA_UID | IMA_FOWNER | IMA_FSUUID | + IMA_INMASK | IMA_EUID | IMA_PCR | + IMA_FSNAME | IMA_DIGSIG_REQUIRED | + IMA_PERMIT_DIRECTIO)) + return false; + + break; + case MODULE_CHECK: case KEXEC_KERNEL_CHECK: case KEXEC_INITRAMFS_CHECK: - case POLICY_CHECK: - /* Validation of these hook functions is in ima_parse_rule() */ + if (entry->flags & ~(IMA_FUNC | IMA_MASK | IMA_FSMAGIC | + IMA_UID | IMA_FOWNER | IMA_FSUUID | + IMA_INMASK | IMA_EUID | IMA_PCR | + IMA_FSNAME | IMA_DIGSIG_REQUIRED | + IMA_PERMIT_DIRECTIO | IMA_MODSIG_ALLOWED | + IMA_CHECK_BLACKLIST)) + return false; + break; case KEXEC_CMDLINE: if (entry->action & ~(MEASURE | DONT_MEASURE)) @@ -1218,7 +1250,6 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) keyrings_len = strlen(args[0].from) + 1; if ((entry->keyrings) || - (entry->func != KEY_CHECK) || (keyrings_len < 2)) { result = -EINVAL; break; @@ -1358,15 +1389,10 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) AUDIT_SUBJ_TYPE); break; case Opt_appraise_type: - if (entry->action != APPRAISE) { - result = -EINVAL; - break; - } - ima_log_string(ab, "appraise_type", args[0].from); if ((strcmp(args[0].from, "imasig")) == 0) entry->flags |= IMA_DIGSIG_REQUIRED; - else if (ima_hook_supports_modsig(entry->func) && + else if (IS_ENABLED(CONFIG_IMA_APPRAISE_MODSIG) && strcmp(args[0].from, "imasig|modsig") == 0) entry->flags |= IMA_DIGSIG_REQUIRED | IMA_MODSIG_ALLOWED; @@ -1374,11 +1400,6 @@ 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 (IS_ENABLED(CONFIG_IMA_APPRAISE_MODSIG) && strstr(args[0].from, "blacklist")) @@ -1390,10 +1411,6 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) entry->flags |= IMA_PERMIT_DIRECTIO; break; case Opt_pcr: - if (entry->action != MEASURE) { - result = -EINVAL; - break; - } ima_log_string(ab, "pcr", args[0].from); result = kstrtoint(args[0].from, 10, &entry->pcr); |