~ruther/guix-local

3993d33d1c0129b1ca6f0fd122fe2bbe48e4f093 — Ludovic Courtès 4 years ago 73d775f
gnu: polkit: Fix CVE-2021-4034.

* gnu/packages/patches/polkit-CVE-2021-4034.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/polkit.scm (polkit-mozjs)[replacement]: New field.
* gnu/packages/polkit.scm (polkit-mozjs/fixed): New variable.
3 files changed, 95 insertions(+), 1 deletions(-)

M gnu/local.mk
A gnu/packages/patches/polkit-CVE-2021-4034.patch
M gnu/packages/polkit.scm
M gnu/local.mk => gnu/local.mk +1 -0
@@ 1645,6 1645,7 @@ dist_patch_DATA =						\
  %D%/packages/patches/plib-CVE-2011-4620.patch		\
  %D%/packages/patches/plib-CVE-2012-4552.patch		\
  %D%/packages/patches/plotutils-spline-test.patch		\
  %D%/packages/patches/polkit-CVE-2021-4034.patch		\
  %D%/packages/patches/polkit-configure-elogind.patch		\
  %D%/packages/patches/polkit-use-duktape.patch			\
  %D%/packages/patches/portaudio-audacity-compat.patch		\

A gnu/packages/patches/polkit-CVE-2021-4034.patch => gnu/packages/patches/polkit-CVE-2021-4034.patch +82 -0
@@ 0,0 1,82 @@
Fixes CVE-2021-4034, local privilege escalation with 'pkexec':

  https://www.openwall.com/lists/oss-security/2022/01/25/11

Patch from <https://gitlab.freedesktop.org/polkit/polkit/-/commit/a2bf5c9c83b6ae46cbd5c779d3055bff81ded683>.

From a2bf5c9c83b6ae46cbd5c779d3055bff81ded683 Mon Sep 17 00:00:00 2001
From: Jan Rybar <jrybar@redhat.com>
Date: Tue, 25 Jan 2022 17:21:46 +0000
Subject: [PATCH] pkexec: local privilege escalation (CVE-2021-4034)

---
 src/programs/pkcheck.c |  5 +++++
 src/programs/pkexec.c  | 23 ++++++++++++++++++++---
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/src/programs/pkcheck.c b/src/programs/pkcheck.c
index f1bb4e1..768525c 100644
--- a/src/programs/pkcheck.c
+++ b/src/programs/pkcheck.c
@@ -363,6 +363,11 @@ main (int argc, char *argv[])
   local_agent_handle = NULL;
   ret = 126;
 
+  if (argc < 1)
+    {
+      exit(126);
+    }
+
   /* Disable remote file access from GIO. */
   setenv ("GIO_USE_VFS", "local", 1);
 
diff --git a/src/programs/pkexec.c b/src/programs/pkexec.c
index 7698c5c..84e5ef6 100644
--- a/src/programs/pkexec.c
+++ b/src/programs/pkexec.c
@@ -488,6 +488,15 @@ main (int argc, char *argv[])
   pid_t pid_of_caller;
   gpointer local_agent_handle;
 
+
+  /*
+   * If 'pkexec' is called THIS wrong, someone's probably evil-doing. Don't be nice, just bail out.
+   */
+  if (argc<1)
+    {
+      exit(127);
+    }
+
   ret = 127;
   authority = NULL;
   subject = NULL;
@@ -614,10 +623,10 @@ main (int argc, char *argv[])
 
       path = g_strdup (pwstruct.pw_shell);
       if (!path)
-	{
+        {
           g_printerr ("No shell configured or error retrieving pw_shell\n");
           goto out;
-	}
+        }
       /* If you change this, be sure to change the if (!command_line)
 	 case below too */
       command_line = g_strdup (path);
@@ -636,7 +645,15 @@ main (int argc, char *argv[])
           goto out;
         }
       g_free (path);
-      argv[n] = path = s;
+      path = s;
+
+      /* argc<2 and pkexec runs just shell, argv is guaranteed to be null-terminated.
+       * /-less shell shouldn't happen, but let's be defensive and don't write to null-termination
+       */
+      if (argv[n] != NULL)
+      {
+        argv[n] = path;
+      }
     }
   if (access (path, F_OK) != 0)
     {

M gnu/packages/polkit.scm => gnu/packages/polkit.scm +12 -1
@@ 1,7 1,7 @@
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2014 Andreas Enge <andreas@enge.fr>
;;; Copyright © 2015 Andy Wingo <wingo@igalia.com>
;;; Copyright © 2015, 2021 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2015, 2021-2022 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2015 Mark H Weaver <mhw@netris.org>
;;; Copyright © 2016 Efraim Flashner <efraim@flashner.co.il>
;;; Copyright © 2017 Huang Ying <huang.ying.caritas@gmail.com>


@@ 54,6 54,7 @@
  (package
    (name "polkit")
    (version "0.120")
    (replacement polkit-mozjs/fixed)
    (source (origin
             (method url-fetch)
             (uri (string-append


@@ 146,6 147,16 @@ making process with respect to granting access to privileged operations
for unprivileged applications.")
    (license lgpl2.0+)))

(define-public polkit-mozjs/fixed
  (package
    (inherit polkit-mozjs)
    (version "0.121")
    (source (origin
              (inherit (package-source polkit-mozjs))
              (patches (cons (search-patch "polkit-CVE-2021-4034.patch")
                             (origin-patches
                              (package-source polkit-mozjs))))))))

;;; Variant of polkit built with Duktape, a lighter JavaScript engine compared
;;; to mozjs.
(define-public polkit-duktape