Unhandled exception in Journalist interface when source no longer exists

[emkll]

Description

There appear to be unhandled exceptions when likely introduced when error handlers wher

Steps to Reproduce

• In journalist interface, navigate to a source page in browser tab 1
• In browser tab 2, navigate to same source, and delete same source
• Refresh the page in browser tab 1
• Observe error 500

Expected Behavior

• Server should return 404

Actual Behavior

• server returns 500

Comments

It seems related to an apparmor issue, the application is trying to redirect to error.html:

journalist-error.log:

[Fri Jul 12 11:32:13.705153 2019] [wsgi:error] [pid 961:tid 4014428063488] ERROR:flask.app:Exception on /favicon.ico [GET]
[Fri Jul 12 11:32:13.705183 2019] [wsgi:error] [pid 961:tid 4014428063488] Traceback (most recent call last):
[Fri Jul 12 11:32:13.705200 2019] [wsgi:error] [pid 961:tid 4014428063488]   File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 2292, in wsgi_app
[Fri Jul 12 11:32:13.705206 2019] [wsgi:error] [pid 961:tid 4014428063488]     response = self.full_dispatch_request()
[Fri Jul 12 11:32:13.705211 2019] [wsgi:error] [pid 961:tid 4014428063488]   File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1815, in full_dispatch_request
[Fri Jul 12 11:32:13.705215 2019] [wsgi:error] [pid 961:tid 4014428063488]     rv = self.handle_user_exception(e)
[Fri Jul 12 11:32:13.705220 2019] [wsgi:error] [pid 961:tid 4014428063488]   File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1713, in handle_user_exception
[Fri Jul 12 11:32:13.705225 2019] [wsgi:error] [pid 961:tid 4014428063488]     return self.handle_http_exception(e)
[Fri Jul 12 11:32:13.705229 2019] [wsgi:error] [pid 961:tid 4014428063488]   File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1644, in handle_http_exception
[Fri Jul 12 11:32:13.706406 2019] [wsgi:error] [pid 961:tid 4014428063488]     return handler(e)
[Fri Jul 12 11:32:13.706415 2019] [wsgi:error] [pid 961:tid 4014428063488]   File "/var/www/securedrop/journalist_app/__init__.py", line 104, in _handle_http_exception
[Fri Jul 12 11:32:13.706421 2019] [wsgi:error] [pid 961:tid 4014428063488]     return render_template('error.html', error=error), error.code
[Fri Jul 12 11:32:13.706426 2019] [wsgi:error] [pid 961:tid 4014428063488]   File "/usr/local/lib/python2.7/dist-packages/flask/templating.py", line 134, in render_template
[Fri Jul 12 11:32:13.706431 2019] [wsgi:error] [pid 961:tid 4014428063488]     return _render(ctx.app.jinja_env.get_or_select_template(template_name_or_list),
[Fri Jul 12 11:32:13.706436 2019] [wsgi:error] [pid 961:tid 4014428063488]   File "/usr/local/lib/python2.7/dist-packages/jinja2/environment.py", line 869, in get_or_select_template
[Fri Jul 12 11:32:13.706441 2019] [wsgi:error] [pid 961:tid 4014428063488]     return self.get_template(template_name_or_list, parent, globals)
[Fri Jul 12 11:32:13.706446 2019] [wsgi:error] [pid 961:tid 4014428063488]   File "/usr/local/lib/python2.7/dist-packages/jinja2/environment.py", line 830, in get_template
[Fri Jul 12 11:32:13.706451 2019] [wsgi:error] [pid 961:tid 4014428063488]     return self._load_template(name, self.make_globals(globals))
[Fri Jul 12 11:32:13.706456 2019] [wsgi:error] [pid 961:tid 4014428063488]   File "/usr/local/lib/python2.7/dist-packages/jinja2/environment.py", line 804, in _load_template
[Fri Jul 12 11:32:13.706461 2019] [wsgi:error] [pid 961:tid 4014428063488]     template = self.loader.load(self, name, globals)
[Fri Jul 12 11:32:13.706466 2019] [wsgi:error] [pid 961:tid 4014428063488]   File "/usr/local/lib/python2.7/dist-packages/jinja2/loaders.py", line 113, in load
[Fri Jul 12 11:32:13.706471 2019] [wsgi:error] [pid 961:tid 4014428063488]     source, filename, uptodate = self.get_source(environment, name)
[Fri Jul 12 11:32:13.706476 2019] [wsgi:error] [pid 961:tid 4014428063488]   File "/usr/local/lib/python2.7/dist-packages/flask/templating.py", line 58, in get_source
[Fri Jul 12 11:32:13.706482 2019] [wsgi:error] [pid 961:tid 4014428063488]     return self._get_source_fast(environment, template)
[Fri Jul 12 11:32:13.706486 2019] [wsgi:error] [pid 961:tid 4014428063488]   File "/usr/local/lib/python2.7/dist-packages/flask/templating.py", line 83, in _get_source_fast
[Fri Jul 12 11:32:13.706492 2019] [wsgi:error] [pid 961:tid 4014428063488]     return loader.get_source(environment, template)
[Fri Jul 12 11:32:13.706496 2019] [wsgi:error] [pid 961:tid 4014428063488]   File "/usr/local/lib/python2.7/dist-packages/jinja2/loaders.py", line 171, in get_source
[Fri Jul 12 11:32:13.706501 2019] [wsgi:error] [pid 961:tid 4014428063488]     f = open_if_exists(filename)
[Fri Jul 12 11:32:13.706506 2019] [wsgi:error] [pid 961:tid 4014428063488]   File "/usr/local/lib/python2.7/dist-packages/jinja2/utils.py", line 154, in open_if_exists
[Fri Jul 12 11:32:13.706511 2019] [wsgi:error] [pid 961:tid 4014428063488]     return open(filename, mode)
[Fri Jul 12 11:32:13.706523 2019] [wsgi:error] [pid 961:tid 4014428063488] IOError: [Errno 13] Permission denied: '/var/www/securedrop/journalist_templates/error.html'
[Fri Jul 12 11:32:13.706852 2019] [wsgi:error] [pid 961:tid 4014428063488] [remote 127.0.0.1:17852] mod_wsgi (pid=961): Exception occurred processing WSGI script '/var/www/journalist.wsgi'.
[Fri Jul 12 11:32:13.706894 2019] [wsgi:error] [pid 961:tid 4014428063488] [remote 127.0.0.1:17852] Traceback (most recent call last):
[Fri Jul 12 11:32:13.706913 2019] [wsgi:error] [pid 961:tid 4014428063488] [remote 127.0.0.1:17852]   File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 2309, in __call__
[Fri Jul 12 11:32:13.706941 2019] [wsgi:error] [pid 961:tid 4014428063488] [remote 127.0.0.1:17852]     return self.wsgi_app(environ, start_response)
[Fri Jul 12 11:32:13.706952 2019] [wsgi:error] [pid 961:tid 4014428063488] [remote 127.0.0.1:17852]   File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 2295, in wsgi_app
[Fri Jul 12 11:32:13.706968 2019] [wsgi:error] [pid 961:tid 4014428063488] [remote 127.0.0.1:17852]     response = self.handle_exception(e)
[Fri Jul 12 11:32:13.706977 2019] [wsgi:error] [pid 961:tid 4014428063488] [remote 127.0.0.1:17852]   File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1748, in handle_exception
[Fri Jul 12 11:32:13.706993 2019] [wsgi:error] [pid 961:tid 4014428063488] [remote 127.0.0.1:17852]     return self.finalize_request(handler(e), from_error_handler=True)
[Fri Jul 12 11:32:13.707002 2019] [wsgi:error] [pid 961:tid 4014428063488] [remote 127.0.0.1:17852]   File "/var/www/securedrop/journalist_app/__init__.py", line 100, in _handle_http_exception
[Fri Jul 12 11:32:13.707018 2019] [wsgi:error] [pid 961:tid 4014428063488] [remote 127.0.0.1:17852]     handler = list(app.error_handler_spec['api'][error.code].values())[0]
[Fri Jul 12 11:32:13.707035 2019] [wsgi:error] [pid 961:tid 4014428063488] [remote 127.0.0.1:17852] AttributeError: 'exceptions.IOError' object has no attribute 'code'

kern.log:

Jul 12 11:32:13 app kernel: [ 1855.913553] audit: type=1400 audit(1562945533.700:15): apparmor="DENIED" operation="open" profile="/usr/sbin/apache2" name="/var/www/securedrop/journalist_templates/error.html" pid=1115 comm="apache2" requested_mask="r" denied_mask="r" fsuid=33 ouid=33

[prateekj117]

@emkll Couldn't reproduce it on my local. Are you sure this still exists?

[zenmonkeykstop]

This was fixed in #5088.