NUVIE: Fix Ultima 6 crash on loading save #4808
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Fix a use-after-free bug. The chain of events causing it is as follows:
In-game the user changes the current view (e.g. by pressing TAB to
go to inventory view). The user next presses ESC to open the
GameMenuDialog and then clicks the "Load Game" button. A save slot is
selected and then loaded.
The resulting call chain is:
GUI_Button::Activate_button()
GameMenuDialog::callback()
GameMenuDialog::close_dialog() <-- This marks GameMenuDialog
for deletion by the GUI
g_engine->loadGameDialog()
GUI::AddWidget() <-------------- This deletes GameMenuDialog
and its children, including
the "Load Game" button
Control then returns to GUI_Button::Activate_button() with "this"
containing the address of the freed button.
An attempt to call Redraw() finally dereferences the invalid pointer.
This is fixed by calling loadGameDialog() before close_dialog().
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Nice. Thanks for tracking down and fixing the problem. |
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Fix a use-after-free bug. The chain of events causing it is as follows:
In-game the user changes the current view (e.g. by pressing TAB to go to inventory view). The user next presses ESC to open the GameMenuDialog and then clicks the "Load Game" button. A save slot is selected and then loaded.
The resulting call chain is:
Control then returns to GUI_Button::Activate_button() with "this" containing the address of the freed button.
An attempt to call Redraw() finally dereferences the invalid pointer.
This is fixed by calling loadGameDialog() before close_dialog().