From 0bed778c53a4f93b1b092b3db33e8c36aabfa39d Mon Sep 17 00:00:00 2001

From: Vit Mojzis <vmojzis@redhat.com>

Date: Tue, 5 Jan 2021 17:00:21 +0100

Subject: [PATCH] python/semanage: empty stdout before exiting on

 BrokenPipeError

Empty stdout buffer before exiting when BrokenPipeError is

encountered. Otherwise python will flush the bufer during exit, which

may trigger the exception again.

https://docs.python.org/3/library/signal.html#note-on-sigpipe

Fixes:

   #semanage fcontext -l | egrep -q -e '^/home'

   BrokenPipeError: [Errno 32] Broken pipe

   Exception ignored in: <_io.TextIOWrapper name='<stdout>' mode='w' encoding='UTF-8'>

   BrokenPipeError: [Errno 32] Broken pipe

Note that the error above only appears occasionally (usually only the

first line is printed).

Signed-off-by: Vit Mojzis <vmojzis@redhat.com>

Acked-by: Nicolas Iooss <nicolas.iooss@m4x.org>

---

 python/semanage/semanage | 8 ++++++++

 1 file changed, 8 insertions(+)

diff --git a/python/semanage/semanage b/python/semanage/semanage

index b2bd9df9..1abe3536 100644

--- a/python/semanage/semanage

+++ b/python/semanage/semanage

@@ -26,6 +26,7 @@

 import traceback

 import argparse

 import sys

+import os

 PROGNAME = "selinux-python"

 try:

     import gettext

@@ -953,6 +954,13 @@ def do_parser():

         args = commandParser.parse_args(make_args(sys.argv))

         args.func(args)

         sys.exit(0)

+    except BrokenPipeError as e:

+        sys.stderr.write("%s: %s\n" % (e.__class__.__name__, str(e)))

+        # Python flushes standard streams on exit; redirect remaining output

+        # to devnull to avoid another BrokenPipeError at shutdown

+        devnull = os.open(os.devnull, os.O_WRONLY)

+        os.dup2(devnull, sys.stdout.fileno())

+        sys.exit(1)

     except IOError as e:

         sys.stderr.write("%s: %s\n" % (e.__class__.__name__, str(e)))

         sys.exit(1)

-- 

2.29.2