Use-after-free in js_print_object in QuickJS

Vulnerability Description

In quickjs, in js_print_object, when printing an array, the function first fetches the array length and then loops over it. The issue is, printing a value is not side-effect free. An attacker-defined callback could run during js_print_value, during which the array could get resized and len1 become out of bounds. This results in a use-after-free.A second instance occurs in the same function during printing of a map or set objects. The code iterates over ms->records list, but once again, elements could be removed from the list during js_print_value call.

References

• https://bellard.org/quickjs/Changelog
• https://issuetracker.google.com/434196651