[Buildroot] [git commit branch/2021.02.x] package/polkit: backport upstream patch to fix CVE-2021-4034
Peter Korsgaard
peter at korsgaard.com
Fri Jan 28 21:55:55 UTC 2022
commit: https://git.buildroot.net/buildroot/commit/?id=90cf9188c96f391ac56788100af326df923b4c37
branch: https://git.buildroot.net/buildroot/commit/?id=refs/heads/2021.02.x
Signed-off-by: Yann E. MORIN <yann.morin.1998 at free.fr>
Cc: Marek Belisko <marek.belisko at open-nandra.com>
Cc: Adam Duskett <aduskett at gmail.com>
Cc: Fabrice Fontaine <fontaine.fabrice at gmail.com>
Signed-off-by: Peter Korsgaard <peter at korsgaard.com>
---
...-local-privilege-escalation-CVE-2021-4034.patch | 80 ++++++++++++++++++++++
package/polkit/polkit.mk | 3 +
2 files changed, 83 insertions(+)
diff --git a/package/polkit/0004-pkexec-local-privilege-escalation-CVE-2021-4034.patch b/package/polkit/0004-pkexec-local-privilege-escalation-CVE-2021-4034.patch
new file mode 100644
index 0000000000..515fdb81c1
--- /dev/null
+++ b/package/polkit/0004-pkexec-local-privilege-escalation-CVE-2021-4034.patch
@@ -0,0 +1,80 @@
+From a2bf5c9c83b6ae46cbd5c779d3055bff81ded683 Mon Sep 17 00:00:00 2001
+From: Jan Rybar <jrybar at redhat.com>
+Date: Tue, 25 Jan 2022 17:21:46 +0000
+Subject: [PATCH] pkexec: local privilege escalation (CVE-2021-4034)
+
+Signed-off-by: "Yann E. MORIN" <yann.morin.1998 at free.fr>
+---
+ 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)
+ {
+--
+2.25.1
+
diff --git a/package/polkit/polkit.mk b/package/polkit/polkit.mk
index e00b634b7f..3fd041a813 100644
--- a/package/polkit/polkit.mk
+++ b/package/polkit/polkit.mk
@@ -12,6 +12,9 @@ POLKIT_CPE_ID_VENDOR = polkit_project
POLKIT_AUTORECONF = YES
POLKIT_INSTALL_STAGING = YES
+# 0004-pkexec-local-privilege-escalation-CVE-2021-4034.patch
+POLKIT_IGNORE_CVE = CVE-2021-4034
+
POLKIT_DEPENDENCIES = \
libglib2 host-intltool expat spidermonkey $(TARGET_NLS_DEPENDENCIES)
More information about the buildroot
mailing list