diff options
Diffstat (limited to 'security/integrity/ima/ima_policy.c')
| -rw-r--r-- | security/integrity/ima/ima_policy.c | 71 |
1 files changed, 61 insertions, 10 deletions
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 6df7f641ff66..4badc4fcda98 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -6,6 +6,9 @@ * ima_policy.c * - initialize default measure policy rules */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include <linux/init.h> #include <linux/list.h> #include <linux/fs.h> @@ -491,6 +494,9 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid, struct ima_rule_entry *entry; int action = 0, actmask = flags | (flags << 1); + if (template_desc) + *template_desc = ima_template_desc_current(); + rcu_read_lock(); list_for_each_entry_rcu(entry, ima_rules, list) { @@ -510,6 +516,7 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid, action |= IMA_FAIL_UNVERIFIABLE_SIGS; } + if (entry->action & IMA_DO_MASK) actmask &= ~(entry->action | entry->action << 1); else @@ -520,8 +527,6 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid, if (template_desc && entry->template) *template_desc = entry->template; - else if (template_desc) - *template_desc = ima_template_desc_current(); if (!actmask) break; @@ -843,6 +848,38 @@ static void ima_log_string(struct audit_buffer *ab, char *key, char *value) ima_log_string_op(ab, key, value, NULL); } +/* + * Validating the appended signature included in the measurement list requires + * the file hash calculated without the appended signature (i.e., the 'd-modsig' + * field). Therefore, notify the user if they have the 'modsig' field but not + * the 'd-modsig' field in the template. + */ +static void check_template_modsig(const struct ima_template_desc *template) +{ +#define MSG "template with 'modsig' field also needs 'd-modsig' field\n" + bool has_modsig, has_dmodsig; + static bool checked; + int i; + + /* We only need to notify the user once. */ + if (checked) + return; + + has_modsig = has_dmodsig = false; + for (i = 0; i < template->num_fields; i++) { + if (!strcmp(template->fields[i]->field_id, "modsig")) + has_modsig = true; + else if (!strcmp(template->fields[i]->field_id, "d-modsig")) + has_dmodsig = true; + } + + if (has_modsig && !has_dmodsig) + pr_notice(MSG); + + checked = true; +#undef MSG +} + static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) { struct audit_buffer *ab; @@ -1128,6 +1165,10 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) 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) && + strcmp(args[0].from, "imasig|modsig") == 0) + entry->flags |= IMA_DIGSIG_REQUIRED | + IMA_MODSIG_ALLOWED; else result = -EINVAL; break; @@ -1181,6 +1222,12 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) else if (entry->action == APPRAISE) temp_ima_appraise |= ima_appraise_flag(entry->func); + if (!result && entry->flags & IMA_MODSIG_ALLOWED) { + template_desc = entry->template ? entry->template : + ima_template_desc_current(); + check_template_modsig(template_desc); + } + audit_log_format(ab, "res=%d", !result); audit_log_end(ab); return result; @@ -1252,6 +1299,12 @@ void ima_delete_rules(void) } } +#define __ima_hook_stringify(str) (#str), + +const char *const func_tokens[] = { + __ima_hooks(__ima_hook_stringify) +}; + #ifdef CONFIG_IMA_READ_POLICY enum { mask_exec = 0, mask_write, mask_read, mask_append @@ -1264,12 +1317,6 @@ static const char *const mask_tokens[] = { "^MAY_APPEND" }; -#define __ima_hook_stringify(str) (#str), - -static const char *const func_tokens[] = { - __ima_hooks(__ima_hook_stringify) -}; - void *ima_policy_start(struct seq_file *m, loff_t *pos) { loff_t l = *pos; @@ -1447,8 +1494,12 @@ int ima_policy_show(struct seq_file *m, void *v) } if (entry->template) seq_printf(m, "template=%s ", entry->template->name); - if (entry->flags & IMA_DIGSIG_REQUIRED) - seq_puts(m, "appraise_type=imasig "); + if (entry->flags & IMA_DIGSIG_REQUIRED) { + if (entry->flags & IMA_MODSIG_ALLOWED) + seq_puts(m, "appraise_type=imasig|modsig "); + else + seq_puts(m, "appraise_type=imasig "); + } if (entry->flags & IMA_PERMIT_DIRECTIO) seq_puts(m, "permit_directio "); rcu_read_unlock(); |