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…s own callback SQLite3::setAuthorizer() frees the previously registered authorizer with zend_fcc_dtor(&db_obj->authorizer_fcc) before installing the new one. The authorizer callback is invoked during statement preparation with db_obj->in_callback incremented, so calling setAuthorizer() from inside the authorizer destroys the fcc that is still executing. For a non-closure callback such as [$obj, 'method'] whose object is only referenced by the fcc, this releases $this while its method is still on the stack, resulting in a use-after-free (closures are kept alive by the call frame, method receivers are not). Reject the call while inside a callback, mirroring the existing guard in SQLite3::close(). createFunction()/createAggregate()/createCollation() append to linked lists and only free their fcc at database close, so they are not affected.
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SQLite3::setAuthorizer() frees the previously registered authorizer with zend_fcc_dtor(&db_obj->authorizer_fcc) before installing the new one. The authorizer callback is invoked during statement preparation with db_obj->in_callback incremented, so calling setAuthorizer() from inside the authorizer destroys the fcc that is still executing. For a non-closure callback such as [$obj, 'method'] whose object is only referenced by the fcc, this releases $this while its method is still on the stack, resulting in a use-after-free (closures are kept alive by the call frame, method receivers are not).
Reject the call while inside a callback, mirroring the existing guard in SQLite3::close(). createFunction()/createAggregate()/createCollation() append to linked lists and only free their fcc at database close, so they are not affected.