fix: prevent activated surface use-after-free on logout

[zorowk]

Ensure the activated surface is safely cleared when logging out or switching sessions by using QPointer and unifying the reset path through setActivatedSurface(nullptr).

Log: prevent activated surface use-after-free on logout
PMS: BUG-347763
Influence: logout

Summary by Sourcery

Bug Fixes:

• Avoid potential use-after-free of the activated surface by making it a QPointer and always clearing it via setActivatedSurface(nullptr).

[deepin-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: zorowk

The full list of commands accepted by this bot can be found here.

Details

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• debian/deepin/OWNERS

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[sourcery-ai]

Reviewer's guide (collapsed on small PRs)

Reviewer's Guide

Refactors how the active/activated surface is cleared on session removal or switch by centralizing the logic through setActivatedSurface(nullptr) and making the activated-surface pointer a QPointer to avoid use-after-free when the underlying QObjects are destroyed, particularly during logout.

Sequence diagram for activated surface reset on logout or session switch

sequenceDiagram
    actor User
    participant SessionManager as Helper
    participant Session
    participant Surface as SurfaceWrapper

    User->>SessionManager: logout()
    SessionManager->>SessionManager: removeSession(session)
    alt session is active
        SessionManager->>SessionManager: m_activeSession.reset()
        SessionManager->>SessionManager: setActivatedSurface(null)
        SessionManager-->>Surface: QPointer cleared
        SessionManager-->>SessionManager: activatedSurfaceChanged signal
    else session not active
        SessionManager->>SessionManager: no changes to activated surface
    end

    User->>SessionManager: switchSession(username, id)
    SessionManager->>SessionManager: updateActiveUserSession(username, id)
    SessionManager->>SessionManager: setActivatedSurface(null)
    SessionManager-->>Surface: QPointer cleared
    SessionManager-->>SessionManager: activatedSurfaceChanged signal
    SessionManager->>SessionManager: update sockets and active session state

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Updated class diagram for Helper activated surface handling

classDiagram
    class QObject

    class SurfaceWrapper {
    }
    SurfaceWrapper --|> QObject

    class Session {
    }

    class Helper {
        - std_weak_ptr_Session m_activeSession
        - QPointer~SurfaceWrapper~ m_activatedSurface
        - LockScreen* m_lockScreen
        - float m_animationSpeed
        - OutputMode m_mode
        - QList~qw_idle_inhibitor_v1*~ m_idleInhibitors
        + void removeSession(std_shared_ptr_Session session)
        + void updateActiveUserSession(QString username, int id)
        + void setActivatedSurface(SurfaceWrapper* surface)
        + void activatedSurfaceChanged()
    }

    Helper o--> Session
    Helper o--> SurfaceWrapper
    Helper o--> LockScreen

    note for Helper "m_activatedSurface is now a QPointer to SurfaceWrapper to prevent use-after-free when the SurfaceWrapper QObject is destroyed"

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File-Level Changes

Change	Details	Files
Centralize and harden activated-surface reset logic to avoid use-after-free on logout/session switch.	Replace direct m_activatedSurface reset and manual activatedSurfaceChanged() emission in removeSession() with a call to setActivatedSurface(nullptr). Remove redundant activatedSurfaceChanged() emission in updateActiveUserSession() and rely on setActivatedSurface(nullptr) to handle state updates and signal emission. Change m_activatedSurface from a raw SurfaceWrapper* to QPointer so it is automatically nulled when the underlying QObject is destroyed, preventing dangling-pointer access.	src/seat/helper.cpp src/seat/helper.h

Possibly linked issues

• #BUG-347763: PR converts activatedSurface to QPointer and clears via setActivatedSurface(nullptr), fixing the Helper::activateSurface crash.

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[sourcery-ai]

Hey - I've left some high level feedback:

• Now that m_activatedSurface is a QPointer, double-check that all remaining call sites go through setActivatedSurface(...) rather than assigning to m_activatedSurface directly, so you don't bypass the unified signaling/cleanup path.
• Given the change to QPointer<SurfaceWrapper>, confirm that setActivatedSurface(nullptr) and any comparisons to m_activatedSurface still behave as intended when the underlying SurfaceWrapper is deleted out from under you (e.g., nullification race conditions in logout/session-switch flows).

Prompt for AI Agents

Please address the comments from this code review:

## Overall Comments
- Now that `m_activatedSurface` is a `QPointer`, double-check that all remaining call sites go through `setActivatedSurface(...)` rather than assigning to `m_activatedSurface` directly, so you don't bypass the unified signaling/cleanup path.
- Given the change to `QPointer<SurfaceWrapper>`, confirm that `setActivatedSurface(nullptr)` and any comparisons to `m_activatedSurface` still behave as intended when the underlying `SurfaceWrapper` is deleted out from under you (e.g., nullification race conditions in logout/session-switch flows).

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[wineee]

理论上窗口销毁前， SurfaceWrapper 应该 unmapped 并发送 requestInactive 信号清理焦点