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Fix use-after-free in ghostty_surface_refresh after sleep/wake (#432) (#619)

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Add nil guard in forceRefresh() to prevent dereferencing freed surface
pointer. Split else-if chains in Workspace.swift so
requestBackgroundSurfaceStartIfNeeded() runs if surface is freed during
the refresh call. Add regression test exercising the crash path.
This commit is contained in:
Lawrence Chen 2026-02-27 01:44:02 -08:00 • committed by GitHub
parent 9ae737026d
commit dca8992901
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GPG key ID: B5690EEEBB952194
3 changed files with 80 additions and 16 deletions
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46
Sources/GhosttyTerminalView.swift
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@ -2007,16 +2007,16 @@ final class TerminalSurface: Identifiable, ObservableObject {
/// Force a full size recalculation and surface redraw.
func forceRefresh() {
let hasSurface = surface != nil
let viewState: String
if let view = attachedView {
let inWindow = view.window != nil
let bounds = view.bounds
let metalOK = (view.layer as? CAMetalLayer) != nil
viewState = "inWindow=\(inWindow) bounds=\(bounds) metalOK=\(metalOK) hasSurface=\(hasSurface)"
} else {
viewState = "NO_ATTACHED_VIEW hasSurface=\(hasSurface)"
}
let hasSurface = surface != nil
let viewState: String
if let view = attachedView {
let inWindow = view.window != nil
let bounds = view.bounds
let metalOK = (view.layer as? CAMetalLayer) != nil
viewState = "inWindow=\(inWindow) bounds=\(bounds) metalOK=\(metalOK) hasSurface=\(hasSurface)"
} else {
viewState = "NO_ATTACHED_VIEW hasSurface=\(hasSurface)"
}
#if DEBUG
let ts = ISO8601DateFormatter().string(from: Date())
let line = "[\(ts)] forceRefresh: \(id) \(viewState)\n"
@ -2028,13 +2028,14 @@ final class TerminalSurface: Identifiable, ObservableObject {
} else {
FileManager.default.createFile(atPath: logPath, contents: line.data(using: .utf8))
}
#endif
#endif
guard let view = attachedView,
view.window != nil,
view.bounds.width > 0,
view.bounds.height > 0 else {
return
}
guard let currentSurface = self.surface else { return }
// Re-read self.surface before each ghostty call to guard against the surface
// being freed during wake-from-sleep geometry reconciliation (issue #432).
@ -2044,10 +2045,9 @@ final class TerminalSurface: Identifiable, ObservableObject {
// Reassert display id on topology churn (split close/reparent) before forcing a refresh.
// This avoids a first-run stuck-vsync state where Ghostty believes vsync is active
// but callbacks have not resumed for the current display.
if let surface = self.surface,
let displayID = (view.window?.screen ?? NSScreen.main)?.displayID,
if let displayID = (view.window?.screen ?? NSScreen.main)?.displayID,
displayID != 0 {
ghostty_surface_set_display_id(surface, displayID)
ghostty_surface_set_display_id(currentSurface, displayID)
}
view.forceRefreshSurface()
@ -2176,6 +2176,24 @@ final class TerminalSurface: Identifiable, ObservableObject {
return ghostty_surface_has_selection(surface)
}
#if DEBUG
/// Test-only helper to deterministically simulate a released runtime surface.
@MainActor
func releaseSurfaceForTesting() {
let callbackContext = surfaceCallbackContext
surfaceCallbackContext = nil
guard let surfaceToFree = surface else {
callbackContext?.release()
return
}
surface = nil
ghostty_surface_free(surfaceToFree)
callbackContext?.release()
}
#endif
deinit {
let callbackContext = surfaceCallbackContext
surfaceCallbackContext = nil