On 12/8/25 16:16, Alyssa Ross wrote:
> Xwayland only accepts connections from the user it's running as.  It
> is started by wayland-proxy-virtwl, which does not allow passing extra
> options, so we can't change its authentication method.
> 
> Therefore, the only way for X11 to work with the current software is
> to run wayland-proxy-virtwl as the same user as the application.
> 
> I expect that in the near future, we will use xwayland-satellite
> instead of the built-in Xwayland translation in wayland-proxy-virtwl.
> When that happens, we can run the stub compositor as its own user
> again.
> 
> Fixes: cb27e3a ("img/app: wayland-proxy-virtwl: run as non-root")
> Signed-off-by: Alyssa Ross <hi@alyssa.is>
> ---
>  img/app/image/etc/group                          | 1 -
>  img/app/image/etc/mdev.conf                      | 2 +-
>  img/app/image/etc/passwd                         | 1 -
>  img/app/image/etc/s6-rc/wayland-proxy-virtwl/run | 2 +-
>  4 files changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/img/app/image/etc/group b/img/app/image/etc/group
> index b2c3a2e..e84da60 100644
> --- a/img/app/image/etc/group
> +++ b/img/app/image/etc/group
> @@ -1,4 +1,3 @@
> -wayland:x:1:wayland
>  wireplumber:x:2:wireplumber
>  pipewire:x:3:pipewire
>  user:x:1000:user
> diff --git a/img/app/image/etc/mdev.conf b/img/app/image/etc/mdev.conf
> index d4cd825..33a07d6 100644
> --- a/img/app/image/etc/mdev.conf
> +++ b/img/app/image/etc/mdev.conf
> @@ -4,7 +4,7 @@
>  -$MODALIAS=.* 0:0 0 ! +importas -Siu MODALIAS modprobe -q $MODALIAS
>  $INTERFACE=.* 0:0 0 ! +/etc/mdev/iface
>  $MODALIAS=virtio:d0000001Av.* 0:0 0 ! +/etc/mdev/virtiofs
> -dri/card0 wayland:wayland 660 +background { /etc/mdev/listen card0 }
> +dri/card0 user:user 660 +background { /etc/mdev/listen card0 }
>  
>  -SUBSYSTEM=sound;.* pipewire:pipewire 660
>  snd/controlC0 pipewire:pipewire 660 +background { /etc/mdev/listen controlC0 }
> diff --git a/img/app/image/etc/passwd b/img/app/image/etc/passwd
> index 08324b0..425908e 100644
> --- a/img/app/image/etc/passwd
> +++ b/img/app/image/etc/passwd
> @@ -1,5 +1,4 @@
>  root:x:0:0:System administrator:/run/root:/bin/sh
> -wayland:x:1:1:wayland-proxy-virtwl service user:/:/usr/bin/nologin
>  wireplumber:x:2:2:WirePlumber service user:/:/usr/bin/nologin
>  pipewire:x:3:3:PipeWire service user:/:/usr/bin/nologin
>  user:x:1000:1000:Spectrum application user:/home/user:/bin/sh
> diff --git a/img/app/image/etc/s6-rc/wayland-proxy-virtwl/run b/img/app/image/etc/s6-rc/wayland-proxy-virtwl/run
> index 86d7f63..5d06b7a 100755
> --- a/img/app/image/etc/s6-rc/wayland-proxy-virtwl/run
> +++ b/img/app/image/etc/s6-rc/wayland-proxy-virtwl/run
> @@ -26,6 +26,6 @@ export LISTEN_FDS 2
>  export LISTEN_FDNAMES wayland:x11
>  getpid LISTEN_PID
>  
> -s6-setuidgid wayland
> +s6-setuidgid user
>  
>  wayland-proxy-virtwl --virtio-gpu --x-display=0
> 
> base-commit: 5104fa720ce8b00612c5487fc47124fbf99e58c6

Might as well also make /tmp/.X11-unix and friends only accessible by
"user".
-- 
Sincerely,
Demi Marie Obenour (she/her/hers)