From d5dafbd5b118a94d0b3e4ea599eeb5a38dcfba6e Mon Sep 17 00:00:00 2001
From: Syed Amer Gilani <syed.amer@gilani.eu>
Date: Thu, 27 Jan 2022 12:06:32 +0100
Subject: [PATCH] polkit: Fix CVE-2021-4034

---
 ...l-privilege-escalation-CVE-2021-4034.patch | 80 +++++++++++++++++++
 .../recipes-extended/polkit/polkit_0.116.bb   |  1 +
 2 files changed, 81 insertions(+)
 create mode 100644 meta-oe/recipes-extended/polkit/files/0001-pkexec-local-privilege-escalation-CVE-2021-4034.patch

diff --git a/meta-oe/recipes-extended/polkit/files/0001-pkexec-local-privilege-escalation-CVE-2021-4034.patch b/meta-oe/recipes-extended/polkit/files/0001-pkexec-local-privilege-escalation-CVE-2021-4034.patch
new file mode 100644
index 00000000000..71bcb7ae202
--- /dev/null
+++ b/meta-oe/recipes-extended/polkit/files/0001-pkexec-local-privilege-escalation-CVE-2021-4034.patch
@@ -0,0 +1,80 @@
+From e3b240b89aa40d6b49e27a5137e7df534e7a9ec2 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)
+
+(cherry picked from commit a2bf5c9c83b6ae46cbd5c779d3055bff81ded683)
+---
+ 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)
+     {
+-- 
+2.34.1
+
diff --git a/meta-oe/recipes-extended/polkit/polkit_0.116.bb b/meta-oe/recipes-extended/polkit/polkit_0.116.bb
index ad1973b136c..8cc2e28ada4 100644
--- a/meta-oe/recipes-extended/polkit/polkit_0.116.bb
+++ b/meta-oe/recipes-extended/polkit/polkit_0.116.bb
@@ -25,6 +25,7 @@ PAM_SRC_URI = "file://polkit-1_pam.patch"
 SRC_URI = "http://www.freedesktop.org/software/polkit/releases/polkit-${PV}.tar.gz \
            ${@bb.utils.contains('DISTRO_FEATURES', 'pam', '${PAM_SRC_URI}', '', d)} \
            file://0003-make-netgroup-support-optional.patch \
+           file://0001-pkexec-local-privilege-escalation-CVE-2021-4034.patch \
            "
 SRC_URI[md5sum] = "4b37258583393e83069a0e2e89c0162a"
 SRC_URI[sha256sum] = "88170c9e711e8db305a12fdb8234fac5706c61969b94e084d0f117d8ec5d34b1"