polkit-0.96-CVE-2021-4034.patch

diff -uNr polkit-0.96/src/programs/pkcheck.c polkit-0.96-new/src/programs/pkcheck.c
--- polkit-0.96/src/programs/pkcheck.c	2022-01-29 13:32:17.257066474 +0800
+++ polkit-0.96-new/src/programs/pkcheck.c	2022-01-29 14:21:03.381476709 +0800
@@ -96,6 +96,8 @@
   allow_user_interaction = FALSE;
   ret = 126;
 
+  if (argc < 1) { exit(126); }
+
   g_type_init ();
 
   details = polkit_details_new ();
diff -uNr polkit-0.96/src/programs/pkexec.c polkit-0.96-new/src/programs/pkexec.c
--- polkit-0.96/src/programs/pkexec.c	2022-01-29 13:32:17.245066321 +0800
+++ polkit-0.96-new/src/programs/pkexec.c	2022-01-29 14:21:48.298050805 +0800
@@ -415,6 +415,8 @@
   gchar *opt_user;
   pid_t pid_of_caller;
 
+  if (argc < 1) { exit(127); }
+
   ret = 127;
   authority = NULL;
   subject = NULL;
@@ -520,7 +522,16 @@
           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)
     {