RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 14:48:14 +00:00
Code Issues Activity Actions

LibJS: Fix UB downcast during GlobalObject construction

Browse source 
When constructing a GlobalObject, it has to pass itself as the global
object to its own Shape. Since this is done in the Object constructor,
and Object is a base class of GlobalObject, it's not yet valid to cast
"this" to a GlobalObject*.

Fix this by having Shape store the global object as an Object& and move
Shape::global_object() to GlobalObject.h where we can at least perform a
valid static_cast in the getter.

Found by oss-fuzz: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=29267
This commit is contained in:
Andreas Kling 2021-01-05 12:02:59 +01:00
parent 279d2eee04
commit fdd974b7ef
4 changed files with 10 additions and 5 deletions
Download patch file Download diff file Expand all files Collapse all files

5
Libraries/LibJS/Runtime/GlobalObject.h
View file

@ -125,4 +125,9 @@ inline void GlobalObject::add_constructor(const FlyString& property_name, Constr
define_property(property_name, constructor, Attribute::Writable | Attribute::Configurable);
}
inline GlobalObject* Shape::global_object() const
{
return static_cast<GlobalObject*>(m_global_object);
}
}