80 lines
2.0 KiB
Diff
80 lines
2.0 KiB
Diff
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)
|
|
{
|
|
--
|
|
GitLab
|
|
|