File CVE-2021-4034-pkexec-fix.patch of Package polkit.22380
--- a/src/programs/pkcheck.c
+++ a/src/programs/pkcheck.c
@@ -363,6 +363,12 @@ main (int argc, char *argv[])
local_agent_handle = NULL;
ret = 126;
+ if (argc < 1)
+ {
+ help();
+ exit(1);
+ }
+
/* Disable remote file access from GIO. */
setenv ("GIO_USE_VFS", "local", 1);
--- a/src/programs/pkexec.c
+++ a/src/programs/pkexec.c
@@ -488,6 +488,17 @@ main (int argc, char *argv[])
pid_t pid_of_caller;
gpointer local_agent_handle;
+
+ /*
+ * If 'pkexec' is called wrong, just show help and bail out.
+ */
+ if (argc<1)
+ {
+ clearenv();
+ usage(argc, argv);
+ exit(1);
+ }
+
ret = 127;
authority = NULL;
subject = NULL;
@@ -614,10 +625,10 @@ 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 +647,15 @@ 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)
{