Fix OOM crashes for huge json documents

Check all places where we reallocate our internal data structure
and return a DocumentTooLarge parse error if we can't get enough
memory.

Change-Id: I006d0170d941837220c7dad0508571b68e2cbfd7
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Kati Kankaanpaa <kati.kankaanpaa@qt.io>
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 4 insertions, 0 deletions

diff --git a/src/corelib/json/qjsonparser_p.h b/src/corelib/json/qjsonparser_p.h
index a395c0c92e..82a7899a51 100644
--- a/src/corelib/json/qjsonparser_p.h
+++ b/src/corelib/json/qjsonparser_p.h
@@ -102,6 +102,10 @@ private:
         if (current + space >= dataLength) {
             dataLength = 2*dataLength + space;
             data = (char *)realloc(data, dataLength);
+            if (!data) {
+                lastError = QJsonParseError::DocumentTooLarge;
+                return -1;
+            }
         }
         int pos = current;
         current += space;