integrity-v6.6

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Merge tag 'integrity-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

Pull integrity subsystem updates from Mimi Zohar:

 - With commit 099f26f22f ("integrity: machine keyring CA
   configuration") certificates may be loaded onto the IMA keyring,
   directly or indirectly signed by keys on either the "builtin" or the
   "machine" keyrings.

   With the ability for the system/machine owner to sign the IMA policy
   itself without needing to recompile the kernel, update the IMA
   architecture specific policy rules to require the IMA policy itself
   be signed.

   [ As commit 099f26f22f was upstreamed in linux-6.4, updating the
     IMA architecture specific policy now to require signed IMA policies
     may break userspace expectations. ]

 - IMA only checked the file data hash was not on the system blacklist
   keyring for files with an appended signature (e.g. kernel modules,
   Power kernel image).

   Check all file data hashes regardless of how it was signed

 - Code cleanup, and a kernel-doc update

* tag 'integrity-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  kexec_lock: Replace kexec_mutex() by kexec_lock() in two comments
  ima: require signed IMA policy when UEFI secure boot is enabled
  integrity: Always reference the blacklist keyring with appraisal
  ima: Remove deprecated IMA_TRUSTED_KEYRING Kconfig

Documentation/ABI/testing/ima_policy

@@ -57,9 +57,9 @@ Description:
 				stored in security.ima xattr. Requires
 				specifying "digest_type=verity" first.)
 
-			appraise_flag:= [check_blacklist]
-			Currently, blacklist check is only for files signed with appended
-			signature.
+			appraise_flag:= [check_blacklist] (deprecated)
+			Setting the check_blacklist flag is no longer necessary.
+			All appraisal functions set it by default.
 			digest_type:= verity
 			    Require fs-verity's file digest instead of the
 			    regular IMA file hash.

arch/powerpc/kernel/ima_arch.c

@@ -23,9 +23,9 @@ bool arch_ima_get_secureboot(void)
  * is not enabled.
  */
 static const char *const secure_rules[] = {
-	"appraise func=KEXEC_KERNEL_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig",
+	"appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig",
 #ifndef CONFIG_MODULE_SIG
-	"appraise func=MODULE_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig",
+	"appraise func=MODULE_CHECK appraise_type=imasig|modsig",
 #endif
 	NULL
 };
@@ -49,9 +49,9 @@ static const char *const trusted_rules[] = {
 static const char *const secure_and_trusted_rules[] = {
 	"measure func=KEXEC_KERNEL_CHECK template=ima-modsig",
 	"measure func=MODULE_CHECK template=ima-modsig",
-	"appraise func=KEXEC_KERNEL_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig",
+	"appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig",
 #ifndef CONFIG_MODULE_SIG
-	"appraise func=MODULE_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig",
+	"appraise func=MODULE_CHECK appraise_type=imasig|modsig",
 #endif
 	NULL
 };

kernel/kexec_file.c

@@ -624,7 +624,7 @@ int kexec_locate_mem_hole(struct kexec_buf *kbuf)
  * kexec_add_buffer - place a buffer in a kexec segment
  * @kbuf:	Buffer contents and memory parameters.
  *
- * This function assumes that kexec_mutex is held.
+ * This function assumes that kexec_lock is held.
  * On successful return, @kbuf->mem will have the physical address of
  * the buffer in memory.
  *

security/integrity/ima/Kconfig

@@ -248,18 +248,6 @@ config IMA_APPRAISE_MODSIG
 	   The modsig keyword can be used in the IMA policy to allow a hook
 	   to accept such signatures.
 
-config IMA_TRUSTED_KEYRING
-	bool "Require all keys on the .ima keyring be signed (deprecated)"
-	depends on IMA_APPRAISE && SYSTEM_TRUSTED_KEYRING
-	depends on INTEGRITY_ASYMMETRIC_KEYS
-	select INTEGRITY_TRUSTED_KEYRING
-	default y
-	help
-	   This option requires that all keys added to the .ima
-	   keyring be signed by a key on the system trusted keyring.
-
-	   This option is deprecated in favor of INTEGRITY_TRUSTED_KEYRING
-
 config IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
 	bool "Permit keys validly signed by a built-in or secondary CA cert (EXPERIMENTAL)"
 	depends on SYSTEM_TRUSTED_KEYRING

security/integrity/ima/ima_appraise.c

@@ -458,11 +458,13 @@ int ima_check_blacklist(struct integrity_iint_cache *iint,
 		ima_get_modsig_digest(modsig, &hash_algo, &digest, &digestsize);
 
 		rc = is_binary_blacklisted(digest, digestsize);
-		if ((rc == -EPERM) && (iint->flags & IMA_MEASURE))
-			process_buffer_measurement(&nop_mnt_idmap, NULL, digest, digestsize,
-						   "blacklisted-hash", NONE,
-						   pcr, NULL, false, NULL, 0);
-	}
+	} else if (iint->flags & IMA_DIGSIG_REQUIRED && iint->ima_hash)
+		rc = is_binary_blacklisted(iint->ima_hash->digest, iint->ima_hash->length);
+
+	if ((rc == -EPERM) && (iint->flags & IMA_MEASURE))
+		process_buffer_measurement(&nop_mnt_idmap, NULL, digest, digestsize,
+					   "blacklisted-hash", NONE,
+					   pcr, NULL, false, NULL, 0);
 
 	return rc;
 }

security/integrity/ima/ima_efi.c

@@ -57,6 +57,9 @@ static const char * const sb_arch_rules[] = {
 	"measure func=KEXEC_KERNEL_CHECK",
 #if !IS_ENABLED(CONFIG_MODULE_SIG)
 	"appraise func=MODULE_CHECK appraise_type=imasig",
+#endif
+#if IS_ENABLED(CONFIG_INTEGRITY_MACHINE_KEYRING) && IS_ENABLED(CONFIG_IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY)
+	"appraise func=POLICY_CHECK appraise_type=imasig",
 #endif
 	"measure func=MODULE_CHECK",
 	NULL

security/integrity/ima/ima_kexec.c

@@ -77,7 +77,7 @@ out:
  * Called during kexec_file_load so that IMA can add a segment to the kexec
  * image for the measurement list for the next kernel.
  *
- * This function assumes that kexec_mutex is held.
+ * This function assumes that kexec_lock is held.
  */
 void ima_add_kexec_buffer(struct kimage *image)
 {

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();