Victor Stinner [Sun, 24 Nov 2019 15:49:23 +0000 (16:49 +0100)]
bpo-38804: Fix REDoS in http.cookiejar (GH-17157) (GH-17345)
The regex http.cookiejar.LOOSE_HTTP_DATE_RE was vulnerable to regular
expression denial of service (REDoS).
LOOSE_HTTP_DATE_RE.match is called when using http.cookiejar.CookieJar
to parse Set-Cookie headers returned by a server.
Processing a response from a malicious HTTP server can lead to extreme
CPU usage and execution will be blocked for a long time.
The regex contained multiple overlapping \s* capture groups.
Ignoring the ?-optional capture groups the regex could be simplified to
\d+-\w+-\d+(\s*\s*\s*)$
Therefore, a long sequence of spaces can trigger bad performance.
class Handler(BaseHTTPRequestHandler):
def do_GET(self):
self.log_request(204)
self.send_response_only(204) # Don't bother sending Server and Date
n_spaces = (
int(self.path[1:]) # Can GET e.g. /100 to test shorter sequences
if len(self.path) > 1 else
65506 # Max header line length 65536
)
value = make_set_cookie_value(n_spaces)
for i in range(99): # Not necessary, but we can have up to 100 header lines
self.send_header("Set-Cookie", value)
self.end_headers()
if __name__ == "__main__":
HTTPServer(("", 44020), Handler).serve_forever()
This server returns 99 Set-Cookie headers. Each has 65506 spaces.
Extracting the cookies will pretty much never complete.
Vulnerable client using the example at the bottom of
https://docs.python.org/3/library/http.cookiejar.html :
import http.cookiejar, urllib.request
cj = http.cookiejar.CookieJar()
opener = urllib.request.build_opener(urllib.request.HTTPCookieProcessor(cj))
r = opener.open("http://localhost:44020/")
The popular requests library was also vulnerable without any additional
options (as it uses http.cookiejar by default):
[2.7] bpo-31036: Allow sphinx and blurb to be found automatically (GH-16638)
Rather than requiring the path to blurb and/or sphinx-build to be specified to the make rule, enhance the Doc/Makefile to look for each first in a virtual environment created by make venv and, if not found, look on the normal process PATH. This allows the Doc/Makefile to take advantage of an installed spinx-build or blurb and, thus, do the right thing most of the time. Also, make the directory for the venv be configurable and document the `make venv` target..
(cherry picked from commit 590665c399fc4aa3c4a9f8e7104d43a02e9f3a0c)
bpo-35036: Remove empty log line in the suspicious.py tool (GH-10024)
Previous to commit ee171a2 the logline was working because of self.info() (now
deprecated) defaults to an empty message.
(cherry picked from commit c3f52a59ce8406d9e59253ad4621e4749abdaeef)
Jason R. Coombs [Tue, 8 Oct 2019 02:00:02 +0000 (22:00 -0400)]
[2.7] bpo-38216, bpo-36274: Allow subclasses to separately override validation and encoding behavior (GH-16476)
Backporting this change, I observe a couple of things:
1. The _encode_request call is no longer meaningful because the request construction will implicitly encode the request using the default encoding when the format string is used (request = '%s %s %s'...). In order to keep the code as consistent as possible, I decided to include the call as a pass-through. I'd be just as happy to remove it entirely, but I'll leave that up to the reviewer to decide. It's okay that this functionality is disabled on Python 2 because this functionality was mainly around bpo-36274, which was mainly a concern with the transition to Python 3.
2. Because _encode_request is no longer meaningful, neither is the test for it, so I've removed that test. Therefore, the meaningful part of this test is that for bpo-38216, adding a (underscore-protected) hook to customize/disable validation.
Kirill Smelkov [Thu, 3 Oct 2019 07:06:52 +0000 (10:06 +0300)]
bpo-38106: Fix race in pthread PyThread_release_lock() (GH-16047)
Fix race in PyThread_release_lock that was leading to memory corruption and
deadlocks. The fix applies to POSIX systems where Python locks are implemented
with mutex and condition variable because POSIX semaphores are either not
provided, or are known to be broken. One particular example of such system is
macOS.
On Darwin, even though this is considered as POSIX, Python uses
mutex+condition variable to implement its lock, and, as of 2019-08-28, Py2.7
implementation, even though similar issue was fixed for Py3 in 2012, contains
synchronization bug: the condition is signalled after mutex unlock while the
correct protocol is to signal condition from under mutex:
Signalling condition outside of corresponding mutex is considered OK by
POSIX, but in Python context it can lead to at least memory corruption if we
consider the whole lifetime of python level lock. For example the following
logical scenario:
# ...
e.g. malloc() which returns memory where sema was
...
# OS scheduler returns control to T2
# sema.release() continues
#
# BUT sema was already freed and writing to anywhere
# inside sema block CORRUPTS MEMORY. In particular if
# _another_ python-level lock was allocated where sema
# block was, writing into the memory can have effect on
# further synchronization correctness and in particular
# lead to deadlock on lock that was next allocated.
pthread_cond_signal(&sema.lock_released)
Note that T2.pthread_cond_signal(&sema.lock_released) CORRUPTS MEMORY as it
is called when sema memory was already freed and is potentially
reallocated for another object.
The fix is to move pthread_cond_signal to be done under corresponding mutex:
(ceval_gil.h is Python3 specific and does not apply to Python2.7)
The bug was there since 1994 - since at least [1]. It was discussed in 2001
with original code author[2], but the code was still considered to be
race-free. In 2010 the place where pthread_cond_signal should be - before or
after pthread_mutex_unlock - was discussed with the rationale to avoid
threads bouncing[3,4,5], and in 2012 pthread_cond_signal was moved to be
called from under mutex, but only for CPython3[6,7].
In 2019 the bug was (re-)discovered while testing Pygolang[8] on macOS with
CPython2 and PyPy2 and PyPy3.
Victor Stinner [Wed, 2 Oct 2019 16:36:32 +0000 (18:36 +0200)]
[2.7] bpo-38338, test.pythoninfo: add more ssl infos (GH-16543)
test.pythoninfo now logs environment variables used by OpenSSL and
Python ssl modules, and logs attributes of 3 SSL contexts
(SSLContext, default HTTPS context, stdlib context).
[2.7] closes bpo-38174: Update vendored expat library to 2.2.8. (GH-16408)
Fixes CVE-2019-15903. See full changelog at https://github.com/libexpat/libexpat/blob/R_2_2_8/expat/Changes..
(cherry picked from commit 52b940803860e37bcc3f6096b2d24e7c20a0e807)
Co-authored-by: Benjamin Peterson <benjamin@python.org>
[2.7] bpo-34155: Dont parse domains containing @ (GH-13079) (GH-16006)
This change skips parsing of email addresses where domains include a "@" character, which can be maliciously used since the local part is returned as a complete address.
[2.7] bpo-35264: Modules/_ssl.c: fix build with OpenSSL 1.1.0 (GH-10570)
Fixes a build error with OpenSSL 1.1.0. There is already code in the
`_ssl.c` that handles all the weird cases of the NPN config macros (with
various OpenSSL & LibreSSL versions).
That code will provide a HAVE_NPN variable, which should be used in the
rest of the code to check whether (or what) to compile regarding NPN.
This change adds HAVE_NPN in the remaining places where it should have been
placed.
Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>
https://bugs.python.org/issue35264
bpo-37445: Include FORMAT_MESSAGE_IGNORE_INSERTS in FormatMessageW() calls (GH-15822)
If FormatMessageW() is passed the FORMAT_MESSAGE_FROM_SYSTEM flag
without FORMAT_MESSAGE_IGNORE_INSERTS, it will fail if there are
insert sequences in the message definition.
(cherry picked from commit a656365)
[2.7] bpo-36502: Update link to UAX GH-44, the Unicode doc on the UCD. (GH-15808)
The link we have points to the version from Unicode 6.0.0, dated 2010.
There have been numerous updates to it since then:
https://www.unicode.org/reports/tr44/GH-Modifications
bpo-35518: Skip test that relies on a deceased network service. (GH-15349)
If this service had thoroughly vanished, we could just ignore the
test until someone gets around to either recreating such a service
or redesigning the test to somehow work locally. The
`support.transient_internet` mechanism catches the failure to
resolve the domain name, and skips the test.
But in fact the domain snakebite.net does still exist, as do its
nameservers -- and they can be quite slow to reply. As a result
this test can easily take 20-30s before it gets auto-skipped.
Ned Deily [Mon, 1 Jul 2019 23:15:09 +0000 (19:15 -0400)]
bpo-19960: Fix building of zlib on macOS without installed headers (GH-14257)
When building 2.7 on macOS without system header files installed in
``/usr/include``, a few extension modules dependent on system-supplied
third-party libraries were not being built, most notably zlib.
This situation arose in the past when building without the Command
Line Tools and the option to install header files in the traditional
system locations (like /usr/include). As of macOS 10.14, the
header files are only available in an SDK so the problem addressed
here affects most 2.7 builds.
Fix test_wsgiref.testEnviron() to no longer depend on the environment
variables (don't fail if "X" variable is set).
testEnviron() now overrides os.environ to get a deterministic
environment. Test full TestHandler.environ content: not only a few
selected variables.
(cherry picked from commit 5150d327924959639215ed0a78feffc0d88258da)
Co-authored-by: Victor Stinner <vstinner@redhat.com>
Victor Stinner [Mon, 24 Jun 2019 11:21:18 +0000 (13:21 +0200)]
bpo-37359: Add --cleanup option to python3 -m test (GH-14332) (GH-14333)
* regrtest: Add --cleanup option to remove "test_python_*" directories
of previous failed test jobs.
* Add "make cleantest" to run "python -m test --cleanup".
Rephrase and clarify that "the entire Python program exits when only daemon threads are left". This matches the documentation at https://docs.python.org/3/library/threading.htmlGH-thread-objects.
(cherry picked from commit bb110cc2ed81447fb48805f31146cf31323a8fc3)
Victor Stinner [Fri, 21 Jun 2019 21:58:53 +0000 (23:58 +0200)]
bpo-37362: test_gdb now ignores stderr (GH-14287) (GH-14297)
test_gdb no longer fails if it gets an "unexpected" message on
stderr: it now ignores stderr. The purpose of test_gdb is to test
that python-gdb.py commands work as expected, not to test gdb.
Victor Stinner [Tue, 11 Jun 2019 10:45:35 +0000 (12:45 +0200)]
[2.7] bpo-36742: Fix urlparse.urlsplit() error message for Unicode URL (GH-13937)
If urlparse.urlsplit() detects an invalid netloc according to NFKC
normalization, the error message type is now str rather than unicode,
and use repr() to format the URL, to prevent <exception str() failed>
when display the error message.