reject package file names that could be used to install local files. Issue reported...

diff --git a/modules/porterbox/files/dd-schroot-cmd b/modules/porterbox/files/dd-schroot-cmd
index 598fb12..41993b2 100755 (executable)
--- a/modules/porterbox/files/dd-schroot-cmd
+++ b/modules/porterbox/files/dd-schroot-cmd
@@ -6,7 +6,7 @@
 ##
 
 
-# Copyright (c) 2013 Peter Palfrader <peter@palfrader.org>
+# Copyright (c) 2013, 2017 Peter Palfrader <peter@palfrader.org>
 #
 # Permission is hereby granted, free of charge, to any person obtaining
 # a copy of this software and associated documentation files (the
@@ -177,9 +177,11 @@ class AptSchroot:
         self.apt_simulate_and_ask(['dist-upgrade'])
 
     def apt_install(self, packages):
+        packages = self.reject_invalid_packages(packages)
         self.apt_simulate_and_ask(['install', '--'] + packages)
 
     def apt_build_dep(self, packages, archonly=False):
+        packages = self.reject_invalid_packages(packages)
         cmd = (['--arch-only'] if archonly else []) + ['build-dep', '--']
         self.apt_simulate_and_ask(cmd + packages)
 
@@ -197,6 +199,21 @@ class AptSchroot:
     def secure_run(self, args, unshare=True):
         WrappedRunner(self.session, args, unshare)
 
+    @staticmethod
+    def reject_invalid_packages(pkgs):
+        """filter package names
+
+        reject package names that start with . or /, as they are
+        not valid package names, but can be used to install local files
+        which we do not want.
+        """
+        new_pkgs = []
+        for p in pkgs:
+            if p.startswith('.') or p.startswith('/'):
+                die("invalid package name: %s"%(p,))
+            new_pkgs.append(p)
+        return new_pkgs
+
 
 parser = optparse.OptionParser()
 parser.set_usage("""%prog [options] -c <session-chroot> [-y] -- <command>