Form 1fa6ef2bc7cee1c8e088dd8b397d9b2d54036dbc Mon Sep 17 00:00:00 2001
From: Rajarishi Devarajan <rishi93dev@gmail.com>
Date: Sun, 12 Jul 2020 23:47:42 +0200
Subject: [PATCH] bpo-39017 Fix infinite loop in the tarfile module

Add a check for length = 0 in the _proc_pax function to avoid running into an infinite loop

Signed-off-by:Rajarishi Devarajan <rishi93dev@gmail.com>

---
 Lib/tarfile.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Lib/tarfile.py b/Lib/tarfile.py
index adf91d5..574a6bb 100644
--- a/Lib/tarfile.py
+++ b/Lib/tarfile.py
@@ -1400,6 +1400,8 @@ class TarInfo(object):
 
             length, keyword = match.groups()
             length = int(length)
+            if length == 0:
+                raise InvalidHeaderError("invalid header")
             value = buf[match.end(2) + 1:match.start(1) + length - 1]
 
             keyword = keyword.decode("utf8")
-- 
2.23.0