<html>
<body>
<div style="font-family: Verdana, Arial, Helvetica, Sans-Serif;">
<table bgcolor="#f9f3c9" width="100%" cellpadding="12" style="border: 1px #c9c399 solid; border-radius: 6px; -moz-border-radius: 6px; -webkit-border-radius: 6px;">
<tr>
<td>
This is an automatically generated e-mail. To reply, visit:
<a href="https://git.reviewboard.kde.org/r/126115/">https://git.reviewboard.kde.org/r/126115/</a>
</td>
</tr>
</table>
<br />
<blockquote style="margin-left: 1em; border-left: 2px solid #d0d0d0; padding-left: 10px;">
<p style="margin-top: 0;">On November 19th, 2015, 2:08 nachm. UTC, <b>Matthias Klumpp</b> wrote:</p>
<blockquote style="margin-left: 1em; border-left: 2px solid #d0d0d0; padding-left: 10px;">
<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;"><p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">Did you consider running the whole script with <code style="text-rendering: inherit;color: #4444cc;padding: 0;white-space: normal;margin: 0;line-height: inherit;">env -i</code>, or (likely the better idea) run KWin with <code style="text-rendering: inherit;color: #4444cc;padding: 0;white-space: normal;margin: 0;line-height: inherit;">env -i</code>?
That should sanitize the environment (unset all env vars, except for shell-defaults). You could then set exactly the variables you need, to the exact values you want, so we don't miss unsetting anything.</p></pre>
</blockquote>
<p>On November 19th, 2015, 2:11 nachm. UTC, <b>Martin Gräßlin</b> wrote:</p>
<blockquote style="margin-left: 1em; border-left: 2px solid #d0d0d0; padding-left: 10px;">
<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;"><p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">No I didn't consider that, because I wasn't aware that this exists.</p></pre>
</blockquote>
<p>On November 19th, 2015, 2:20 nachm. UTC, <b>Martin Gräßlin</b> wrote:</p>
<blockquote style="margin-left: 1em; border-left: 2px solid #d0d0d0; padding-left: 10px;">
<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;"><p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">Just tried with changing directly in the wayland session file. That doesn't work at all. I think the main problem is that I lose important env variables related to the logind session/dbus, etc.</p>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">So only way would be for the command to start kwin_wayland. But that as well would require to set quite an amount of env variables, but worth a try.</p></pre>
</blockquote>
<p>On November 19th, 2015, 2:55 nachm. UTC, <b>Martin Gräßlin</b> wrote:</p>
<blockquote style="margin-left: 1em; border-left: 2px solid #d0d0d0; padding-left: 10px;">
<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;"><p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">Just gave a try - the command looks horrible, but I got the session started and env variables are properly filtered.</p>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">Command looks like this now:
/usr/bin/env -i KDE_FULL_SESSION=true KDE_SESSION_VERSION=5 KDE_SESSION_UID=${KDE_SESSION_UID} XDG_CURRENT_DESKTOP=KDE QT_QPA_PLATFORM=wayland PAM_KWALLET5_LOGIN=${PAM_KWALLET5_LOGIN} USER=${USER} LANGUAGE=${LANGUAGE} XDG_SEAT=${XDG_SEAT} XDG_SESSION_TYPE=${XDG_SESSION_TYPE} XCURSOR_SIZE=${XCURSOR_SIZE} HOME=${HOME} DESKTOP_SESSION=${DESKTOP_SESSION} XDG_SEAT_PATH=${XDG_SEAT_PATH} DBUS_SESSION_BUS_ADDRESS=${DBUS_SESSION_BUS_ADDRESS} LOGNAME=${LOGNAME} XDG_SESSION_CLASS=${XDG_SESSION_CLASS} XDG_SESSION_ID=${XDG_SESSION_ID} PATH=${PATH} XDG_SESSION_PATH=${XDG_SESSION_PATH} XDG_RUNTIME_DIR=${XDG_RUNTIME_DIR} XCURSOR_THEME=${XCURSOR_THEME} LANG=${LANG} XDG_SESSION_DESKTOP=${XDG_SESSION_DESKTOP} XCURSOR_PATH=${XCURSOR_PATH} XDG_VTNR=${XDG_VTNR} PWD=${PWD} XDG_DATA_DIRS=${XDG_DATA_DIRS} XDG_CONFIG_DIRS=${XDG_CONFIG_DIRS} @KWIN_WAYLAND_BIN_PATH@ --xwayland --libinput --exit-with-session=@CMAKE_INSTALL_FULL_LIBEXECDIR@/startplasma</p></pre>
</blockquote>
</blockquote>
<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;"><p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">Urgh, terrible! But I think this might just be the best workaround we can come up with, given the circumstances. It at least protects against someone adding new env vars which load bad code into the compositor. It might be an issue as soon as kwin starts to require another env var which isn't in the list, but that's an issue we can solve.
I wonder if we can simplify that command somehow, though, e.g. by placing the allowed variables in a file or new variable, to make this easier to read.
Apart from that, +1 from me (I'll take a look at other DEs though, maybe someone has come up with a bettr solution to this issue).</p></pre>
<br />
<p>- Matthias</p>
<br />
<p>On November 19th, 2015, 12:22 nachm. UTC, Martin Gräßlin wrote:</p>
<table bgcolor="#fefadf" width="100%" cellspacing="0" cellpadding="12" style="border: 1px #888a85 solid; border-radius: 6px; -moz-border-radius: 6px; -webkit-border-radius: 6px;">
<tr>
<td>
<div>Review request for Plasma, David Edmundson and Matthias Klumpp.</div>
<div>By Martin Gräßlin.</div>
<p style="color: grey;"><i>Updated Nov. 19, 2015, 12:22 nachm.</i></p>
<div style="margin-top: 1.5em;">
<b style="color: #575012; font-size: 10pt;">Repository: </b>
plasma-workspace
</div>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description </h1>
<table width="100%" bgcolor="#ffffff" cellspacing="0" cellpadding="10" style="border: 1px solid #b8b5a0">
<tr>
<td>
<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">Any environment variable which can be used to specify a path to a
binary object to be loaded in the KWin process bears the risk of
being abused to add code to KWin to perform as a key logger.
E.g. an env variable pointing QT_PLUGIN_PATH to a location in $HOME
and adjusting QT_STYLE_OVERRIDE to load a specific QStyle plugin from
that location would allow to easily log all keys without KWin noticing.
As env variables can be specified in scripts sourced before the session
starts there is not much KWin can do about that to protect itself.
This affects all the LD_* variables and any library KWin uses and
loads plugins.
The list here is based on what I could find:
* LD_* variables as specified in the man page
* LIBGL_* and EGL_* as specified on mesa page
* QT_* variables based on "git grep qgetenv" in qtbase and qtdeclarative
combined with Qt's documentation
* "git grep getenv" in various KDE frameworks based on ldd output of KWin
Unfortunately the list is unlikely to be complete. If one env variable is
missed, there is a risk. Even more each change in any library might
introduce new variables.
The approach is futile, but needed till Linux has a secure way to start
the session without sourcing env variable scripts from user owned
locations.</pre>
</td>
</tr>
</table>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
<ul style="margin-left: 3em; padding-left: 0;">
<li>startkde/startplasmacompositor.cmake <span style="color: grey">(1e46e5be0a0d733fb01e1a87a34ee3c73a06bf8c)</span></li>
</ul>
<p><a href="https://git.reviewboard.kde.org/r/126115/diff/" style="margin-left: 3em;">View Diff</a></p>
</td>
</tr>
</table>
</div>
</body>
</html>