[Scummvm-git-logs] scummvm master -> 55136a8f7e2ae07e0937464b359f48a6ddc98263

[antoniou79]

This automated email contains information about 1 new commit which have been
pushed to the 'scummvm' repo located at https://github.com/scummvm/scummvm .

Summary:
55136a8f7e SKY: Prevent manual save to slot 0


Commit: 55136a8f7e2ae07e0937464b359f48a6ddc98263
    https://github.com/scummvm/scummvm/commit/55136a8f7e2ae07e0937464b359f48a6ddc98263
Author: antoniou79 (a.antoniou79 at gmail.com)
Date: 2020-07-21T16:57:38+03:00

Commit Message:
SKY: Prevent manual save to slot 0

Slot 0 is reserved for autosave but ScummVM in-game would allow saving on it

This was causing segmentation fault (_selectedGame would overflow and also saveGameTexts would be indexed with a -1 index

Changed paths:
    engines/sky/control.cpp
    engines/sky/detection.cpp
    engines/sky/sky.cpp


diff --git a/engines/sky/control.cpp b/engines/sky/control.cpp
index ec8eac003f..07a56cef7b 100644
--- a/engines/sky/control.cpp
+++ b/engines/sky/control.cpp
@@ -1140,7 +1140,7 @@ void Control::saveDescriptions(const Common::StringArray &list) {
 
 	outf = _saveFileMan->openForSaving("SKY-VM.SAV");
 	bool ioFailed = true;
-	if (outf) {
+	if (outf != nullptr) {
 		for (uint16 cnt = 0; cnt < MAX_SAVE_GAMES; cnt++) {
 			outf->write(list[cnt].c_str(), list[cnt].size() + 1);
 		}
@@ -1162,7 +1162,7 @@ uint16 Control::saveGameToFile(bool fromControlPanel, const char *filename, bool
 
 	Common::OutSaveFile *outf;
 	outf = _saveFileMan->openForSaving(filename);
-	if (outf == NULL)
+	if (outf == nullptr)
 		return NO_DISK_SPACE;
 
 	if (!fromControlPanel) {
diff --git a/engines/sky/detection.cpp b/engines/sky/detection.cpp
index 16275cfe26..60224e2d0a 100644
--- a/engines/sky/detection.cpp
+++ b/engines/sky/detection.cpp
@@ -385,6 +385,13 @@ Common::Error SkyEngine::loadGameState(int slot) {
 }
 
 Common::Error SkyEngine::saveGameState(int slot, const Common::String &desc, bool isAutosave) {
+	// prevent writing to autosave slot when user selects it manually
+	// ie. from the ScummVM in-game menu Save panel
+	// This also secures _selectedGame which is unsigned integer (uint16)
+	// from overflowing in the subtraction below
+	if (!isAutosave && slot <= 0) {
+		return Common::kWritePermissionDenied;
+	}
 	// Set the save slot and save the game
 	_skyControl->_selectedGame = isAutosave ? 0 : slot - 1;
 	if (_skyControl->saveGameToFile(false, nullptr, isAutosave) != GAME_SAVED)
diff --git a/engines/sky/sky.cpp b/engines/sky/sky.cpp
index 7e86ee7a5c..d8fc9c4b02 100644
--- a/engines/sky/sky.cpp
+++ b/engines/sky/sky.cpp
@@ -171,7 +171,7 @@ Common::Error SkyEngine::go() {
 	uint16 result = 0;
 	if (ConfMan.hasKey("save_slot")) {
 		int saveSlot = ConfMan.getInt("save_slot");
-		if (saveSlot >= 0 && saveSlot <= 999)
+		if (saveSlot >= 0 && saveSlot <= MAX_SAVE_GAMES)
 			result = _skyControl->quickXRestore(ConfMan.getInt("save_slot"));
 	}