diff options
| author | Lars Knoll <lars.knoll@qt.io> | 2016-11-02 14:10:47 +0100 |
|---|---|---|
| committer | Giuseppe D'Angelo <giuseppe.dangelo@kdab.com> | 2016-11-11 12:34:27 +0000 |
| commit | bfaa8925d5cc0a59cec3f747a8d982ca819f026b (patch) | |
| tree | f50e0fde4e197fee070fc2906b16085352b45328 /src/corelib/json/qjson.cpp | |
| parent | 3c2cb87de2554b9c4f6e2080768fe9ede00aeab3 (diff) | |
Improve the validation algorithm for binary JSON
Add better boundary checks and catch (hopefully all)
cases where invalid binary JSON could cause crashes.
Change-Id: I206510b7c5e3ba953802a5f46645878e65704ecc
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Diffstat (limited to 'src/corelib/json/qjson.cpp')
| -rw-r--r-- | src/corelib/json/qjson.cpp | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/src/corelib/json/qjson.cpp b/src/corelib/json/qjson.cpp index c3b58e59a50..c6fff068ce1 100644 --- a/src/corelib/json/qjson.cpp +++ b/src/corelib/json/qjson.cpp @@ -129,10 +129,12 @@ bool Data::valid() const return false; bool res = false; - if (header->root()->is_object) - res = static_cast<Object *>(header->root())->isValid(); + Base *root = header->root(); + int maxSize = alloc - sizeof(Header); + if (root->is_object) + res = static_cast<Object *>(root)->isValid(maxSize); else - res = static_cast<Array *>(header->root())->isValid(); + res = static_cast<Array *>(root)->isValid(maxSize); return res; } @@ -195,9 +197,9 @@ int Object::indexOf(const QString &key, bool *exists) return min; } -bool Object::isValid() const +bool Object::isValid(int maxSize) const { - if (tableOffset + length*sizeof(offset) > size) + if (size > (uint)maxSize || tableOffset + length*sizeof(offset) > size) return false; QString lastKey; @@ -206,8 +208,7 @@ bool Object::isValid() const if (entryOffset + sizeof(Entry) >= tableOffset) return false; Entry *e = entryAt(i); - int s = e->size(); - if (table()[i] + s > tableOffset) + if (!e->isValid(tableOffset - table()[i])) return false; QString key = e->key(); if (key < lastKey) @@ -221,9 +222,9 @@ bool Object::isValid() const -bool Array::isValid() const +bool Array::isValid(int maxSize) const { - if (tableOffset + length*sizeof(offset) > size) + if (size > (uint)maxSize || tableOffset + length*sizeof(offset) > size) return false; for (uint i = 0; i < length; ++i) { @@ -323,12 +324,12 @@ bool Value::isValid(const Base *b) const int s = usedStorage(b); if (!s) return true; - if (s < 0 || offset + s > (int)b->tableOffset) + if (s < 0 || s > (int)b->tableOffset - offset) return false; if (type == QJsonValue::Array) - return static_cast<Array *>(base(b))->isValid(); + return static_cast<Array *>(base(b))->isValid(s); if (type == QJsonValue::Object) - return static_cast<Object *>(base(b))->isValid(); + return static_cast<Object *>(base(b))->isValid(s); return true; } |