Merge commit 'tags/keys-fixes-20171018' into fixes-v4.14-rc5

4 files changed, 37 insertions, 8 deletions

diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c
index 018c588c7ac3..8e704d12a1cf 100644
--- a/fs/crypto/keyinfo.c
+++ b/fs/crypto/keyinfo.c
@@ -109,6 +109,11 @@ static int validate_user_key(struct fscrypt_info *crypt_info,
 		goto out;
 	}
 	ukp = user_key_payload_locked(keyring_key);
+	if (!ukp) {
+		/* key was revoked before we acquired its semaphore */
+		res = -EKEYREVOKED;
+		goto out;
+	}
 	if (ukp->datalen != sizeof(struct fscrypt_key)) {
 		res = -EINVAL;
 		goto out;
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index 9c351bf757b2..3fbc0ff79699 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -84,11 +84,16 @@ struct ecryptfs_page_crypt_context {
 static inline struct ecryptfs_auth_tok *
 ecryptfs_get_encrypted_key_payload_data(struct key *key)
 {
-	if (key->type == &key_type_encrypted)
-		return (struct ecryptfs_auth_tok *)
-			(&((struct encrypted_key_payload *)key->payload.data[0])->payload_data);
-	else
+	struct encrypted_key_payload *payload;
+
+	if (key->type != &key_type_encrypted)
 		return NULL;
+
+	payload = key->payload.data[0];
+	if (!payload)
+		return ERR_PTR(-EKEYREVOKED);
+
+	return (struct ecryptfs_auth_tok *)payload->payload_data;
 }
 
 static inline struct key *ecryptfs_get_encrypted_key(char *sig)
@@ -114,12 +119,17 @@ static inline struct ecryptfs_auth_tok *
 ecryptfs_get_key_payload_data(struct key *key)
 {
 	struct ecryptfs_auth_tok *auth_tok;
+	struct user_key_payload *ukp;
 
 	auth_tok = ecryptfs_get_encrypted_key_payload_data(key);
-	if (!auth_tok)
-		return (struct ecryptfs_auth_tok *)user_key_payload_locked(key)->data;
-	else
+	if (auth_tok)
 		return auth_tok;
+
+	ukp = user_key_payload_locked(key);
+	if (!ukp)
+		return ERR_PTR(-EKEYREVOKED);
+
+	return (struct ecryptfs_auth_tok *)ukp->data;
 }
 
 #define ECRYPTFS_MAX_KEYSET_SIZE 1024
diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index 3cf1546dca82..fa218cd64f74 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -459,7 +459,8 @@ out:
  * @auth_tok_key: key containing the authentication token
  * @auth_tok: authentication token
  *
- * Returns zero on valid auth tok; -EINVAL otherwise
+ * Returns zero on valid auth tok; -EINVAL if the payload is invalid; or
+ * -EKEYREVOKED if the key was revoked before we acquired its semaphore.
  */
 static int
 ecryptfs_verify_auth_tok_from_key(struct key *auth_tok_key,
@@ -468,6 +469,12 @@ ecryptfs_verify_auth_tok_from_key(struct key *auth_tok_key,
 	int rc = 0;
 
 	(*auth_tok) = ecryptfs_get_key_payload_data(auth_tok_key);
+	if (IS_ERR(*auth_tok)) {
+		rc = PTR_ERR(*auth_tok);
+		*auth_tok = NULL;
+		goto out;
+	}
+
 	if (ecryptfs_verify_version((*auth_tok)->version)) {
 		printk(KERN_ERR "Data structure version mismatch. Userspace "
 		       "tools must match eCryptfs kernel module with major "
diff --git a/fs/fscache/object-list.c b/fs/fscache/object-list.c
index b5ab06fabc60..0438d4cd91ef 100644
--- a/fs/fscache/object-list.c
+++ b/fs/fscache/object-list.c
@@ -331,6 +331,13 @@ static void fscache_objlist_config(struct fscache_objlist_data *data)
 	rcu_read_lock();
 
 	confkey = user_key_payload_rcu(key);
+	if (!confkey) {
+		/* key was revoked */
+		rcu_read_unlock();
+		key_put(key);
+		goto no_config;
+	}
+
 	buf = confkey->data;
 
 	for (len = confkey->datalen - 1; len >= 0; len--) {