[3.9] gh-95778: CVE-2020-10735: Prevent DoS by very large int() (#96502)
* Correctly pre-check for int-to-str conversion (#96537)
Converting a large enough `int` to a decimal string raises `ValueError` as expected. However, the raise comes _after_ the quadratic-time base-conversion algorithm has run to completion. For effective DOS prevention, we need some kind of check before entering the quadratic-time loop. Oops! =)
The quick fix: essentially we catch _most_ values that exceed the threshold up front. Those that slip through will still be on the small side (read: sufficiently fast), and will get caught by the existing check so that the limit remains exact.
The justification for the current check. The C code check is:
```c
max_str_digits / (3 * PyLong_SHIFT) <= (size_a - 11) / 10
```
In GitHub markdown math-speak, writing $M$ for `max_str_digits`, $L$ for `PyLong_SHIFT` and $s$ for `size_a`, that check is:
$$\left\lfloor\frac{M}{3L}\right\rfloor \le \left\lfloor\frac{s - 11}{10}\right\rfloor$$
From this it follows that
$$\frac{M}{3L} < \frac{s-1}{10}$$
hence that
$$\frac{L(s-1)}{M} > \frac{10}{3} > \log_2(10).$$
So
$$2^{L(s-1)} > 10^M.$$
But our input integer $a$ satisfies $|a| \ge 2^{L(s-1)}$, so $|a|$ is larger than $10^M$. This shows that we don't accidentally capture anything _below_ the intended limit in the check.
Co-authored-by: Gregory P. Smith [Google LLC] <greg@krypto.org> Co-authored-by: Christian Heimes <christian@python.org> Co-authored-by: Mark Dickinson <dickinsm@gmail.com>
Gbp-Pq: Name 0002-3.9-gh-95778-CVE-2020-10735-Prevent-DoS-by-very-larg.patch
Matthias Klose [Thu, 20 Mar 2025 02:07:39 +0000 (10:07 +0800)]
langpack-gettext
# DP: Description: support alternative gettext tree in
# DP: /usr/share/locale-langpack; if a file is present in both trees,
# DP: prefer the newer one
# DP: Upstream status: Ubuntu-Specific
# DP: Description: support alternative gettext tree in
# DP: /usr/share/locale-langpack; if a file is present in both trees,
# DP: prefer the newer one
# DP: Upstream status: Ubuntu-Specific
Matthias Klose [Thu, 20 Mar 2025 02:07:39 +0000 (10:07 +0800)]
distutils-sysconfig
# DP: Get CONFIGURE_CFLAGS, CONFIGURE_CPPFLAGS, CONFIGURE_LDFLAGS from
# DP: the python build, when CFLAGS, CPPFLAGS, LDSHARED) are not set
# DP: in the environment.
# DP: Get CONFIGURE_CFLAGS, CONFIGURE_CPPFLAGS, CONFIGURE_LDFLAGS from
# DP: the python build, when CFLAGS, CPPFLAGS, LDSHARED) are not set
# DP: in the environment.
Matthias Klose [Thu, 20 Mar 2025 02:07:39 +0000 (10:07 +0800)]
distutils-install-layout
# DP: distutils: Add an option --install-layout=deb, which
# DP: - installs into $prefix/dist-packages instead of $prefix/site-packages.
# DP: - doesn't encode the python version into the egg name.
# DP: distutils: Add an option --install-layout=deb, which
# DP: - installs into $prefix/dist-packages instead of $prefix/site-packages.
# DP: - doesn't encode the python version into the egg name.
[ Bastien Roucariès ]
* Fix CVE-2025-0938:
The Python standard library functions `urllib.parse.urlsplit` and
`urlparse` accepted domain names that included square brackets
which isn't valid according to RFC 3986.
Square brackets are only meant to be used as delimiters for specifying
IPv6 and IPvFuture hosts in URLs. This could result in differential
parsing across the Python URL parser and other specification-compliant
URL parsers.
[ Sean Whitton ]
- Fix CVE-2022-0391: Missing input sanitisation when parsing URLs, which
could lead to injection accounts.
- Fix CVE-2025-1795: The implementation of e-mail header parsing and
folding would encode the comma used to separate list items which could
cause receiving applications to interpret two items in the list as
though they were one item.
projects / python3.9.git / log