commit 93582ed64185f375f2c44ebda8d94f4d9ed09fc8
author aPiecek <piecek@cesnet.cz> Tue May 25 14:49:06 2021 +0200
committer Michal Vasko <mvasko@cesnet.cz> Wed May 26 16:10:13 2021 +0200
tree 80e58625dcfc05b854521bc38fbb32c24ec70c3d
parent 274203acbd2279f61b01df19a6f26f7839e30106

parser BUGFIX stack-oveflow protection

In yang/json format by tracking the right and left braces.
In xml by tracking open and close element.

src/parser_yang.c

diff --git a/src/parser_yang.c b/src/parser_yang.c
index 4c76d43..7e5cc98 100644
--- a/src/parser_yang.c
+++ b/src/parser_yang.c
@@ -751,7 +751,18 @@
     word_start = ctx->in->current;
     *kw = lysp_match_kw(ctx->in, &ctx->indent);
 
-    if ((*kw == LY_STMT_SYNTAX_SEMICOLON) || (*kw == LY_STMT_SYNTAX_LEFT_BRACE) || (*kw == LY_STMT_SYNTAX_RIGHT_BRACE)) {
+    if (*kw == LY_STMT_SYNTAX_SEMICOLON) {
+        goto success;
+    } else if (*kw == LY_STMT_SYNTAX_LEFT_BRACE) {
+        ctx->depth++;
+        if (ctx->depth > LY_MAX_BLOCK_DEPTH) {
+            LOGERR(ctx->parsed_mod->mod->ctx, LY_EINVAL,
+                    "The maximum number of block nestings has been exceeded.");
+            return LY_EINVAL;
+        }
+        goto success;
+    } else if (*kw == LY_STMT_SYNTAX_RIGHT_BRACE) {
+        ctx->depth--;
         goto success;
     }