update: Linux Overview security updates (#2690)

- Remove Wayland section
- Add Permission Controls section

Signed-off-by: Daniel Gray <dngray@privacyguides.org>
Signed-off-by: Jonah Aragon <jonah@privacyguides.org>

docs/desktop.md

@@ -16,7 +16,7 @@ Linux distributions are commonly recommended for privacy protection and software
 
 ![Fedora logo](assets/img/linux-desktop/fedora.svg){ align=right }
 
-**Fedora Workstation** is our recommended distribution for people new to Linux. Fedora generally adopts newer technologies before other distributions e.g., [Wayland](https://wayland.freedesktop.org) and [PipeWire](https://pipewire.org). These new technologies often come with improvements in security, privacy, and usability in general.
+**Fedora Workstation** is our recommended distribution for people new to Linux. Fedora generally adopts newer technologies (e.g., [Wayland](https://wayland.freedesktop.org) and [PipeWire](https://pipewire.org)) before other distributions. These new technologies often come with improvements in security, privacy, and usability in general.
 
 [:octicons-home-16: Homepage](https://fedoraproject.org/workstation){ .md-button .md-button--primary }
 [:octicons-info-16:](https://docs.fedoraproject.org/en-US/docs){ .card-link title=Documentation}
@@ -90,11 +90,11 @@ A large portion of [Arch Linux’s packages](https://reproducible.archlinux.org)
 
 </div>
 
-[Fedora Atomic Desktops](https://fedoramagazine.org/introducing-fedora-atomic-desktops) come in a variety of flavors depending on the desktop environment you prefer, such as **Fedora Silverblue** (which comes with [GNOME](https://gnome.org)), **Fedora Kinoite** (which comes with [KDE](https://kde.org)), **Fedora Sway Atomic**, or **Fedora Budgie Atomic**. However, we don't recommend the last of these as the Budgie desktop environment [still requires X11](https://buddiesofbudgie.org/blog/wayland).
+[Fedora Atomic Desktops](https://fedoramagazine.org/introducing-fedora-atomic-desktops) come in a variety of flavors depending on the desktop environment you prefer. As with the recommendation to avoid X11 in our [criteria](#criteria) for Linux distributions, we recommend avoiding flavors that support only the legacy X11 window system.
 
 These operating systems differ from Fedora Workstation as they replace the [DNF](https://docs.fedoraproject.org/en-US/quick-docs/dnf) package manager with a much more advanced alternative called [`rpm-ostree`](https://docs.fedoraproject.org/en-US/fedora/latest/system-administrators-guide/package-management/rpm-ostree). The `rpm-ostree` package manager works by downloading a base image for the system, then overlaying packages over it in a [git](https://en.wikipedia.org/wiki/Git)-like commit tree. When the system is updated, a new base image is downloaded and the overlays will be applied to that new image.
 
-After the update is complete you will reboot the system into the new deployment. `rpm-ostree` keeps two deployments of the system so that you can easily roll back if something breaks in the new deployment. There is also the option to pin more deployments as needed.
+After the update is complete, you will reboot the system into the new deployment. `rpm-ostree` keeps two deployments of the system so that you can easily roll back if something breaks in the new deployment. There is also the option to pin more deployments as needed.
 
 [Flatpak](https://flatpak.org) is the primary package installation method on these distributions, as `rpm-ostree` is only meant to overlay packages that cannot stay inside of a container on top of the base image.
 
@@ -124,7 +124,7 @@ The Nix package manager uses a purely functional language—which is also called
 
 [Nixpkgs](https://github.com/nixos/nixpkgs) (the main source of packages) are contained in a single GitHub repository. You can also define your own packages in the same language and then easily include them in your config.
 
-Nix is a source-based package manager; if there’s no pre-built available in the binary cache, Nix will just build the package from source using its definition. It builds each package in a sandboxed *pure* environment, which is as independent of the host system as possible, thus making binaries reproducible.
+Nix is a source-based package manager; if there’s no pre-built available in the binary cache, Nix will just build the package from source using its definition. It builds each package in a sandboxed *pure* environment, which is as independent of the host system as possible. Binaries built with this method are reproducible, which can be useful as a safeguard against [:material-package-variant-closed-remove: Supply Chain Attacks](basics/common-threats.md#attacks-against-certain-organizations){ .pg-viridian }.
 
 ## Anonymity-Focused Distributions
 
@@ -231,8 +231,8 @@ Choosing a Linux distro that is right for you will come down to a huge variety o
 
 - Free and open source.
 - Receives regular software and kernel updates.
-- [Avoids X11](os/linux-overview.md#wayland).
+- Avoids X11, as its last major release was [more than a decade](https://www.x.org/wiki/Releases) ago.
-    - The notable exception here is Qubes, but the isolation issues which X11 typically has are avoided by virtualization. This isolation only applies to apps *running in different qubes* (virtual machines); apps running in the *same* qube are not protected from each other.
+    - The notable exception here is Qubes, but the [isolation issues](https://blog.invisiblethings.org/2011/04/23/linux-security-circus-on-gui-isolation) which X11 typically has are avoided by virtualization. This isolation only applies to apps *running in different qubes* (virtual machines); apps running in the *same* qube are not protected from each other.
 - Supports full-disk encryption during installation.
 - Doesn't freeze regular releases for more than 1 year.
     - We [recommend against](os/linux-overview.md#release-cycle) "Long Term Support" or "stable" distro releases for desktop usage.

docs/os/linux-overview.md

@@ -102,14 +102,6 @@ Consider using [ZRAM](https://wiki.archlinux.org/title/Zram#Using_zram-generator
 
 If you require suspend-to-disk (hibernation) functionality, you will still need to use a traditional swap file or partition. Make sure that any swap space you do have on a persistent storage device is [encrypted](https://wiki.archlinux.org/title/Dm-crypt/Swap_encryption) at a minimum to mitigate some of these threats.
 
-### Wayland
-
-We recommend using a desktop environment that supports the [Wayland](https://en.wikipedia.org/wiki/Wayland_(display_server_protocol)) display protocol, as it was developed with security [in mind](https://lwn.net/Articles/589147). Its predecessor ([X11](https://en.wikipedia.org/wiki/X_Window_System)) does not support GUI isolation, which allows any window to [record, log, and inject inputs in other windows](https://blog.invisiblethings.org/2011/04/23/linux-security-circus-on-gui-isolation.html), making any attempt at sandboxing futile.
-
-Fortunately, [Wayland compositors](https://en.wikipedia.org/wiki/Wayland_(protocol)#Wayland_compositors) such as those included with [GNOME](https://gnome.org) and [KDE Plasma](https://kde.org) now have good support for Wayland along with some other compositors that use [wlroots](https://gitlab.freedesktop.org/wlroots/wlroots/-/wikis/Projects-which-use-wlroots), (e.g. [Sway](https://swaywm.org)). Some distributions like Fedora and Tumbleweed use it by default, and some others may do so in the future as X11 is in [hard maintenance mode](https://phoronix.com/news/X.Org-Maintenance-Mode-Quickly). If you’re using one of those environments, it is as easy as selecting the “Wayland” session at the desktop display manager ([GDM](https://en.wikipedia.org/wiki/GNOME_Display_Manager), [SDDM](https://en.wikipedia.org/wiki/Simple_Desktop_Display_Manager)).
-
-We recommend **against** using desktop environments or window managers that do not have Wayland support, such as Cinnamon (default on Linux Mint), Pantheon (default on Elementary OS), MATE, Xfce, and i3.
-
 ### Proprietary Firmware (Microcode Updates)
 
 Some Linux distributions (such as [Linux-libre](https://en.wikipedia.org/wiki/Linux-libre)-based or DIY distros) don’t come with the proprietary [microcode](https://en.wikipedia.org/wiki/Microcode) updates which patch critical security vulnerabilities. Some notable examples of these vulnerabilities include [Spectre](https://en.wikipedia.org/wiki/Spectre_(security_vulnerability)), [Meltdown](https://en.wikipedia.org/wiki/Meltdown_(security_vulnerability)), [SSB](https://en.wikipedia.org/wiki/Speculative_Store_Bypass), [Foreshadow](https://en.wikipedia.org/wiki/Foreshadow), [MDS](https://en.wikipedia.org/wiki/Microarchitectural_Data_Sampling), [SWAPGS](https://en.wikipedia.org/wiki/SWAPGS_(security_vulnerability)), and other [hardware vulnerabilities](https://kernel.org/doc/html/latest/admin-guide/hw-vuln/index.html).
@@ -124,6 +116,22 @@ Some distributions (particularly those aimed at advanced users) are more bare bo
 
 Additionally, some distributions will not download firmware updates automatically. For that, you will need to install [`fwupd`](https://wiki.archlinux.org/title/Fwupd).
 
+### Permission Controls
+
+Desktop environments (DEs) that support the [Wayland](https://wayland.freedesktop.org) display protocol are [more secure](https://lwn.net/Articles/589147) than those that only support X11. However, not all DEs take full advantage of Wayland's architectural security improvements.
+
+For example, GNOME has a notable edge in security compared to other DEs by implementing permission controls for third-party software that tries to [capture your screen](https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/3943). That is, when a third-party application attempts to capture your screen, you are prompted for your permission to share your screen with the app.
+
+<figure markdown>
+  ![Screenshot permissions](../assets/img/linux/screenshot_permission.png){ width="450" }
+  <figcaption>GNOME's screenshot permission dialog</figcaption>
+</figure>
+
+Many alternatives don't provide these same permission controls yet,[^1] while some are waiting for Wayland to implement these controls upstream.[^2]
+
+[^1]: KDE currently has an open proposal to add controls for screen captures: <https://invent.kde.org/plasma/xdg-desktop-portal-kde/-/issues/7>
+[^2]: Sway is waiting to add specific security controls until they "know how security as a whole is going to play out" in Wayland: <https://github.com/swaywm/sway/issues/5118#issuecomment-600054496>
+
 ## Privacy Tweaks
 
 ### MAC Address Randomization