From: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Date: Mon, 25 Sep 2023 17:32:22 +0000 (+0100)
Subject: tools/pygrub: Small refactors
X-Git-Tag: RELEASE-4.15.6~54
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=844bcf0274938489caa8e431915c93f01b61b443;p=xen.git

tools/pygrub: Small refactors

Small tidy up to ensure output_directory always has a trailing '/' to ease
concatenating paths and that `output` can only be a filename or None.

This is part of XSA-443 / CVE-2023-34325

Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
(cherry picked from commit 9f2ff9a7c9b3ac734ae99f17f0134ed0343dcccf)
---

diff --git a/tools/pygrub/src/pygrub b/tools/pygrub/src/pygrub
index ce4e07d3e8..1042c05b86 100755
--- a/tools/pygrub/src/pygrub
+++ b/tools/pygrub/src/pygrub
@@ -793,7 +793,7 @@ if __name__ == "__main__":
     debug = False
     not_really = False
     output_format = "sxp"
-    output_directory = "/var/run/xen/pygrub"
+    output_directory = "/var/run/xen/pygrub/"
 
     # what was passed in
     incfg = { "kernel": None, "ramdisk": None, "args": "" }
@@ -815,7 +815,8 @@ if __name__ == "__main__":
             usage()
             sys.exit()
         elif o in ("--output",):
-            output = a
+            if a != "-":
+                output = a
         elif o in ("--kernel",):
             incfg["kernel"] = a
         elif o in ("--ramdisk",):
@@ -847,12 +848,11 @@ if __name__ == "__main__":
             if not os.path.isdir(a):
                 print("%s is not an existing directory" % a)
                 sys.exit(1)
-            output_directory = a
+            output_directory = a + '/'
 
     if debug:
         logging.basicConfig(level=logging.DEBUG)
 
-
     try:
         os.makedirs(output_directory, 0o700)
     except OSError as e:
@@ -861,7 +861,7 @@ if __name__ == "__main__":
         else:
             raise
 
-    if output is None or output == "-":
+    if output is None:
         fd = sys.stdout.fileno()
     else:
         fd = os.open(output, os.O_WRONLY)