core: fs_htree: include meta in root hash

Includes the meta data when calculating the hash of the root node to
detect changes in file length while number of blocks is unchanged.

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Reviewed-by: Jerome Forissier <jerome.forissier@linaro.org>
Fixes: #2094
Reported-by: Kevin Peng <kevinp@marvell.com>
Tested-by: Kevin Peng <kevinp@marvell.com>
[jf: add Fixes:, Reported-by: and Tested-by: tags]
Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>

core/tee/fs_htree.c

@@ -397,7 +397,8 @@ static TEE_Result init_tree_from_data(struct tee_fs_htree *ht)
 	return TEE_SUCCESS;
 }
 
-static TEE_Result calc_node_hash(struct htree_node *node, void *ctx,
+static TEE_Result calc_node_hash(struct htree_node *node,
+				 struct tee_fs_htree_meta *meta, void *ctx,
 				 uint8_t *digest)
 {
 	TEE_Result res;
@@ -413,6 +414,12 @@ static TEE_Result calc_node_hash(struct htree_node *node, void *ctx,
 	if (res != TEE_SUCCESS)
 		return res;
 
+	if (meta) {
+		res = crypto_hash_update(ctx, alg, (void *)meta, sizeof(meta));
+		if (res != TEE_SUCCESS)
+			return res;
+	}
+
 	if (node->child[0]) {
 		res = crypto_hash_update(ctx, alg, node->child[0]->node.hash,
 					 sizeof(node->child[0]->node.hash));
@@ -563,7 +570,10 @@ static TEE_Result verify_node(struct traverse_arg *targ,
 	TEE_Result res;
 	uint8_t digest[TEE_FS_HTREE_HASH_SIZE];
 
-	res = calc_node_hash(node, ctx, digest);
+	if (node->parent)
+		res = calc_node_hash(node, NULL, ctx, digest);
+	else
+		res = calc_node_hash(node, &targ->ht->imeta.meta, ctx, digest);
 	if (res == TEE_SUCCESS &&
 	    buf_compare_ct(digest, node->node.hash, sizeof(digest)))
 		return TEE_ERROR_CORRUPT_OBJECT;
@@ -598,7 +608,8 @@ static TEE_Result init_root_node(struct tee_fs_htree *ht)
 	ht->root.id = 1;
 	ht->root.dirty = true;
 
-	res = calc_node_hash(&ht->root, ctx, ht->root.node.hash);
+	res = calc_node_hash(&ht->root, &ht->imeta.meta, ctx,
+			     ht->root.node.hash);
 	crypto_hash_free_ctx(ctx, TEE_FS_HTREE_HASH_ALG);
 
 	return res;
@@ -670,6 +681,7 @@ struct tee_fs_htree_meta *tee_fs_htree_get_meta(struct tee_fs_htree *ht)
 void tee_fs_htree_meta_set_dirty(struct tee_fs_htree *ht)
 {
 	ht->dirty = true;
+	ht->root.dirty = true;
 }
 
 static TEE_Result free_node(struct traverse_arg *targ __unused,
@@ -694,6 +706,7 @@ static TEE_Result htree_sync_node_to_storage(struct traverse_arg *targ,
 {
 	TEE_Result res;
 	uint8_t vers;
+	struct tee_fs_htree_meta *meta = NULL;
 
 	/*
 	 * The node can be dirty while the block isn't updated due to
@@ -717,9 +730,10 @@ static TEE_Result htree_sync_node_to_storage(struct traverse_arg *targ,
 		 * writing the header.
 		 */
 		vers = !(targ->ht->head.counter & 1);
+		meta = &targ->ht->imeta.meta;
 	}
 
-	res = calc_node_hash(node, targ->arg, node->node.hash);
+	res = calc_node_hash(node, meta, targ->arg, node->node.hash);
 	if (res != TEE_SUCCESS)
 		return res;