Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity into next-integrity

From: Mimi Zohar <zohar@linux.ibm.com>

Linux 5.0 introduced the platform keyring to allow verifying the IMA
kexec kernel image signature using the pre-boot keys.  This pull
request similarly makes keys on the platform keyring accessible for
verifying the PE kernel image signature.*

Also included in this pull request is a new IMA hook that tags tmp
files, in policy, indicating the file hash needs to be calculated.
 The remaining patches are cleanup.

*Upstream commit "993a110319a4 (x86/kexec: Fix a kexec_file_load()
failure)" is required for testing.

arch/x86/kernel/kexec-bzimage64.c

@@ -531,9 +531,17 @@ static int bzImage64_cleanup(void *loader_data)
 #ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
 static int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len)
 {
-	return verify_pefile_signature(kernel, kernel_len,
-				       VERIFY_USE_SECONDARY_KEYRING,
-				       VERIFYING_KEXEC_PE_SIGNATURE);
+	int ret;
+
+	ret = verify_pefile_signature(kernel, kernel_len,
+				      VERIFY_USE_SECONDARY_KEYRING,
+				      VERIFYING_KEXEC_PE_SIGNATURE);
+	if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING)) {
+		ret = verify_pefile_signature(kernel, kernel_len,
+					      VERIFY_USE_PLATFORM_KEYRING,
+					      VERIFYING_KEXEC_PE_SIGNATURE);
+	}
+	return ret;
 }
 #endif
 

certs/system_keyring.c

@@ -24,6 +24,9 @@ static struct key *builtin_trusted_keys;
 #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
 static struct key *secondary_trusted_keys;
 #endif
+#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
+static struct key *platform_trusted_keys;
+#endif
 
 extern __initconst const u8 system_certificate_list[];
 extern __initconst const unsigned long system_certificate_list_size;
@@ -237,11 +240,22 @@ int verify_pkcs7_signature(const void *data, size_t len,
 #else
 		trusted_keys = builtin_trusted_keys;
 #endif
+	} else if (trusted_keys == VERIFY_USE_PLATFORM_KEYRING) {
+#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
+		trusted_keys = platform_trusted_keys;
+#else
+		trusted_keys = NULL;
+#endif
+		if (!trusted_keys) {
+			ret = -ENOKEY;
+			pr_devel("PKCS#7 platform keyring is not available\n");
+			goto error;
+		}
 	}
 	ret = pkcs7_validate_trust(pkcs7, trusted_keys);
 	if (ret < 0) {
 		if (ret == -ENOKEY)
-			pr_err("PKCS#7 signature not signed with a trusted key\n");
+			pr_devel("PKCS#7 signature not signed with a trusted key\n");
 		goto error;
 	}
 
@@ -266,3 +280,10 @@ error:
 EXPORT_SYMBOL_GPL(verify_pkcs7_signature);
 
 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
+
+#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
+void __init set_platform_trusted_keys(struct key *keyring)
+{
+	platform_trusted_keys = keyring;
+}
+#endif

fs/namei.c

@@ -3462,6 +3462,7 @@ struct dentry *vfs_tmpfile(struct dentry *dentry, umode_t mode, int open_flag)
 		inode->i_state |= I_LINKABLE;
 		spin_unlock(&inode->i_lock);
 	}
+	ima_post_create_tmpfile(inode);
 	return child;
 
 out_err:

include/keys/system_keyring.h

@@ -61,5 +61,13 @@ static inline struct key *get_ima_blacklist_keyring(void)
 }
 #endif /* CONFIG_IMA_BLACKLIST_KEYRING */
 
+#if defined(CONFIG_INTEGRITY_PLATFORM_KEYRING) && \
+	defined(CONFIG_SYSTEM_TRUSTED_KEYRING)
+extern void __init set_platform_trusted_keys(struct key *keyring);
+#else
+static inline void set_platform_trusted_keys(struct key *keyring)
+{
+}
+#endif
 
 #endif /* _KEYS_SYSTEM_KEYRING_H */

include/linux/ima.h

@@ -18,6 +18,7 @@ struct linux_binprm;
 #ifdef CONFIG_IMA
 extern int ima_bprm_check(struct linux_binprm *bprm);
 extern int ima_file_check(struct file *file, int mask);
+extern void ima_post_create_tmpfile(struct inode *inode);
 extern void ima_file_free(struct file *file);
 extern int ima_file_mmap(struct file *file, unsigned long prot);
 extern int ima_load_data(enum kernel_load_data_id id);
@@ -56,6 +57,10 @@ static inline int ima_file_check(struct file *file, int mask)
 	return 0;
 }
 
+static inline void ima_post_create_tmpfile(struct inode *inode)
+{
+}
+
 static inline void ima_file_free(struct file *file)
 {
 	return;

include/linux/verification.h

@@ -17,6 +17,7 @@
  * should be used.
  */
 #define VERIFY_USE_SECONDARY_KEYRING ((struct key *)1UL)
+#define VERIFY_USE_PLATFORM_KEYRING  ((struct key *)2UL)
 
 /*
  * The use to which an asymmetric key is being put.

security/integrity/digsig.c

@@ -87,6 +87,9 @@ static int __integrity_init_keyring(const unsigned int id, key_perm_t perm,
 		pr_info("Can't allocate %s keyring (%d)\n",
 			keyring_name[id], err);
 		keyring[id] = NULL;
+	} else {
+		if (id == INTEGRITY_KEYRING_PLATFORM)
+			set_platform_trusted_keys(keyring[id]);
 	}
 
 	return err;

security/integrity/evm/evm_crypto.c

@@ -173,8 +173,7 @@ static void hmac_add_misc(struct shash_desc *desc, struct inode *inode,
 	crypto_shash_update(desc, (const u8 *)&hmac_misc, sizeof(hmac_misc));
 	if ((evm_hmac_attrs & EVM_ATTR_FSUUID) &&
 	    type != EVM_XATTR_PORTABLE_DIGSIG)
-		crypto_shash_update(desc, &inode->i_sb->s_uuid.b[0],
-				    sizeof(inode->i_sb->s_uuid));
+		crypto_shash_update(desc, (u8 *)&inode->i_sb->s_uuid, UUID_SIZE);
 	crypto_shash_final(desc, digest);
 }
 

security/integrity/evm/evm_main.c

@@ -563,7 +563,6 @@ static int __init init_evm(void)
 {
 	int error;
 	struct list_head *pos, *q;
-	struct xattr_list *xattr;
 
 	evm_init_config();
 
@@ -580,11 +579,8 @@ static int __init init_evm(void)
 error:
 	if (error != 0) {
 		if (!list_empty(&evm_config_xattrnames)) {
-			list_for_each_safe(pos, q, &evm_config_xattrnames) {
-				xattr = list_entry(pos, struct xattr_list,
-						   list);
+			list_for_each_safe(pos, q, &evm_config_xattrnames)
 				list_del(pos);
-			}
 		}
 	}
 

security/integrity/ima/ima_main.c

@@ -396,6 +396,33 @@ int ima_file_check(struct file *file, int mask)
 }
 EXPORT_SYMBOL_GPL(ima_file_check);
 
+/**
+ * ima_post_create_tmpfile - mark newly created tmpfile as new
+ * @file : newly created tmpfile
+ *
+ * No measuring, appraising or auditing of newly created tmpfiles is needed.
+ * Skip calling process_measurement(), but indicate which newly, created
+ * tmpfiles are in policy.
+ */
+void ima_post_create_tmpfile(struct inode *inode)
+{
+	struct integrity_iint_cache *iint;
+	int must_appraise;
+
+	must_appraise = ima_must_appraise(inode, MAY_ACCESS, FILE_CHECK);
+	if (!must_appraise)
+		return;
+
+	/* Nothing to do if we can't allocate memory */
+	iint = integrity_inode_get(inode);
+	if (!iint)
+		return;
+
+	/* needed for writing the security xattrs */
+	set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
+	iint->ima_file_status = INTEGRITY_PASS;
+}
+
 /**
  * ima_post_path_mknod - mark as a new inode
  * @dentry: newly created dentry
@@ -413,9 +440,13 @@ void ima_post_path_mknod(struct dentry *dentry)
 	if (!must_appraise)
 		return;
 
+	/* Nothing to do if we can't allocate memory */
 	iint = integrity_inode_get(inode);
-	if (iint)
-		iint->flags |= IMA_NEW_FILE;
+	if (!iint)
+		return;
+
+	/* needed for re-opening empty files */
+	iint->flags |= IMA_NEW_FILE;
 }
 
 /**

security/keys/encrypted-keys/encrypted.c

@@ -60,11 +60,11 @@ static int blksize;
 static struct crypto_shash *hash_tfm;
 
 enum {
-	Opt_err = -1, Opt_new, Opt_load, Opt_update
+	Opt_new, Opt_load, Opt_update, Opt_err
 };
 
 enum {
-	Opt_error = -1, Opt_default, Opt_ecryptfs, Opt_enc32
+	Opt_default, Opt_ecryptfs, Opt_enc32, Opt_error
 };
 
 static const match_table_t key_format_tokens = {