python3-pip: fix CVE-2021-3572

Backport the body of a fix for CVE-2021-3572 since hardknott carries
20.0.2, and the delta between it and the latest 21.1.3 is more than just
bugfixes.

CVE: CVE-2021-3572

(From OE-Core rev: fb7a2af241795b82f121381cea6f4b56ce948ebf)

Signed-off-by: Trevor Gamblin <trevor.gamblin@windriver.com>
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/python/python3-pip/0001-Don-t-split-git-references-on-unicode-separators.patch

@@ -0,0 +1,40 @@
+From 25c1b92b1add0b81afe2fc6f9e82f66738a2d800 Mon Sep 17 00:00:00 2001
+From: Trevor Gamblin <trevor.gamblin@windriver.com>
+Date: Thu, 22 Jul 2021 09:57:53 -0400
+Subject: [PATCH] Don't split git references on unicode separators
+
+Upstream-Status: Backport 
+(https://github.com/pypa/pip/commit/e46bdda9711392fec0c45c1175bae6db847cb30b)
+
+CVE: CVE-2021-3572
+
+Signed-off-by: Trevor Gamblin <trevor.gamblin@windriver.com>
+---
+ src/pip/_internal/vcs/git.py | 10 ++++++++--
+ 1 file changed, 8 insertions(+), 2 deletions(-)
+
+diff --git a/src/pip/_internal/vcs/git.py b/src/pip/_internal/vcs/git.py
+index 7483303a9..d706064e7 100644
+--- a/src/pip/_internal/vcs/git.py
++++ b/src/pip/_internal/vcs/git.py
+@@ -137,9 +137,15 @@ class Git(VersionControl):
+         output = cls.run_command(['show-ref', rev], cwd=dest,
+                                  show_stdout=False, on_returncode='ignore')
+         refs = {}
+-        for line in output.strip().splitlines():
++        # NOTE: We do not use splitlines here since that would split on other
++        #       unicode separators, which can be maliciously used to install a
++        #       different revision.
++        for line in output.strip().split("\n"):
++            line = line.rstrip("\r")
++            if not line:
++                continue
+             try:
+-                sha, ref = line.split()
++                sha, ref = line.split(" ", maxsplit=2)
+             except ValueError:
+                 # Include the offending line to simplify troubleshooting if
+                 # this error ever occurs.
+-- 
+2.31.1
+

meta/recipes-devtools/python/python3-pip_20.0.2.bb

@@ -6,7 +6,9 @@ LIC_FILES_CHKSUM = "file://LICENSE.txt;md5=8ba06d529c955048e5ddd7c45459eb2e"
 
 DEPENDS += "python3 python3-setuptools-native"
 
-SRC_URI += "file://0001-change-shebang-to-python3.patch"
+SRC_URI += "file://0001-change-shebang-to-python3.patch \
+            file://0001-Don-t-split-git-references-on-unicode-separators.patch \
+            "
 
 SRC_URI[md5sum] = "7d42ba49b809604f0df3d55df1c3fd86"
 SRC_URI[sha256sum] = "7db0c8ea4c7ea51c8049640e8e6e7fde949de672bfa4949920675563a5a6967f"