Verified Commit 06987a39 authored by Ray Kraesig's avatar Ray Kraesig Committed by ma1
Browse files

Bug 1950056 - extend use of FOS_NODEREFERENCELINKS r=Gijs,win-reviewers,gstoll 

In the modern era of user-customizable Quick Access sidebars on every
file dialog, navigating via `.lnk` files is rather less useful than it
was twenty years ago.

Disable link-following in file-open dialogs by default, to prevent any
of the usual security issues involving symlink smuggling. Allow
overriding this behavior via a pref, for users who don't care.

(File-save dialogs have a more nuanced guard against that sort of thing;
this patch doesn't affect that.)

Differential Revision: https://phabricator.services.mozilla.com/D239833
parent 3ce005c0

modules/libpref/init/StaticPrefList.yaml

+11 −0
Original line number Diff line number Diff line
@@ -15784,6 +15784,17 @@ 
  value: 0

  mirror: always



# Whether to follow `.lnk` (etc.) shortcuts in the Windows file-open dialog.

#

# Valid values:

#  * 0: never

#  * 1: always

#  * 2: auto

- name: widget.windows.follow_shortcuts_on_file_open

  type: RelaxedAtomicInt32

  value: 2

  mirror: always



# The number of messages of each type to keep for display in

# about:windows-messages

- name: widget.windows.messages_to_log

widget/windows/nsFilePicker.cpp

+18 −7
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include "mozilla/Assertions.h"

#include "mozilla/BackgroundHangMonitor.h"

#include "mozilla/ProfilerLabels.h"

#include "mozilla/StaticPrefs_widget.h"

#include "mozilla/UniquePtr.h"

#include "mozilla/WindowsVersion.h"

#include "nsReadableUtils.h"
@@ -181,19 +182,29 @@ bool nsFilePicker::ShowFilePicker(const nsString& aInitialDir) { 


    // mode specific

    switch (mMode) {

      case modeOpenMultiple:

        fos |= FOS_ALLOWMULTISELECT;

        [[fallthrough]];



      case modeOpen:

        fos |= FOS_FILEMUSTEXIST;

        switch (mozilla::StaticPrefs::

                    widget_windows_follow_shortcuts_on_file_open()) {

          case 1:

            break;



      case modeOpenMultiple:

        fos |= FOS_FILEMUSTEXIST | FOS_ALLOWMULTISELECT;

          default:

            fos |= FOS_NODEREFERENCELINKS;

        }

        break;



      case modeSave:

        fos |= FOS_NOREADONLYRETURN;

        // Don't follow shortcuts when saving a shortcut, this can be used

        // to trick users (bug 271732)

        if (IsDefaultPathLink()) fos |= FOS_NODEREFERENCELINKS;

        // Don't follow shortcuts when saving a shortcut; this can be used to

        // trick users (bug 271732). _Do_ follow shortcuts when not saving a

        // shortcut (bug 283730).

        if (IsDefaultPathLink()) {

          fos |= FOS_NODEREFERENCELINKS;

        }

        break;



      case modeGetFolder: