[3.12] gh-119451: Fix a potential denial of service in http.client (GH-119454) (#142140)
gh-119451: Fix a potential denial of service in http.client (GH-119454)
Reading the whole body of the HTTP response could cause OOM if
the Content-Length value is too large even if the server does not send
a large amount of data. Now the HTTP client reads large data by chunks,
therefore the amount of consumed memory is proportional to the amount
of sent data.
(cherry picked from commit 5a4c4a033a4a54481be6870aa1896fad732555b5)
Serhiy Storchaka [Mon, 22 Dec 2025 13:49:44 +0000 (15:49 +0200)]
[3.12] gh-119342: Fix a potential denial of service in plistlib (GH-119343) (#142149)
Reading a specially prepared small Plist file could cause OOM because file's
read(n) preallocates a bytes object for reading the specified amount of
data. Now plistlib reads large data by chunks, therefore the upper limit of
consumed memory is proportional to the size of the input file.
(cherry picked from commit 694922cf40aa3a28f898b5f5ee08b71b4922df70)
Co-authored-by: Jacob Walls <38668450+jacobtylerwalls@users.noreply.github.com> Co-authored-by: Seth Michael Larson <seth@python.org> Co-authored-by: Petr Viktorin <encukou@gmail.com> Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com> Co-authored-by: Gregory P. Smith <68491+gpshead@users.noreply.github.com> Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com> Co-authored-by: Gregory P. Smith <68491+gpshead@users.noreply.github.com> Co-authored-by: Gregory P. Smith <greg@krypto.org>
[3.12] gh-90949: add Expat API to prevent XML deadly allocations (CVE-2025-59375) (GH-139234) (#139527)
* [3.12] gh-90949: add Expat API to prevent XML deadly allocations (CVE-2025-59375) (GH-139234)
Expose the XML Expat 2.7.2 mitigation APIs to disallow use of
disproportional amounts of dynamic memory from within an Expat
parser (see CVE-2025-59375 for instance).
The exposed APIs are available on Expat parsers, that is,
parsers created by `xml.parsers.expat.ParserCreate()`, as:
- `parser.SetAllocTrackerActivationThreshold(threshold)`, and
- `parser.SetAllocTrackerMaximumAmplification(max_factor)`.
[3.12] gh-119452: Fix a potential virtual memory allocation denial of service in http.server (GH-142216) (#142297)
[3.14] gh-119452: Fix a potential virtual memory allocation denial of service in http.server (GH-142216)
The CGI server on Windows could consume the amount of memory specified
in the Content-Length header of the request even if the client does not
send such much data. Now it reads the POST request body by chunks,
therefore the memory consumption is proportional to the amount of sent
data.
(cherry picked from commit 0e4f4f1a4633f2d215fb5a803cae278aeea31845)
[3.12] gh-139310: skip `test_aead_aes_gcm` for Linux kernel between 6.16.0 and 6.17.x (GH-139552) (GH-139764)
Currently, Fedora 42 uses a custom Linux Kernel 6.16.9 that backported an upstream change
from 6.17-rc7 [1,3] but not its subsequent fix [2]. Until the issue is resolved upstream,
we skip the failing test `test_socket.test_aead_aes_gcm` for kernel versions between 6.16
and 6.17.x.
Support records with "zip64 extensible data" if there are no bytes
prepended to the ZIP file.
(cherry picked from commit 162997bb70e067668c039700141770687bc8f267)
[3.12] gh-139400: Make sure that parent parsers outlive their subparsers in `pyexpat` (GH-139403) (GH-139609)
Within libexpat, a parser created via `XML_ExternalEntityParserCreate`
is relying on its parent parser throughout its entire lifetime.
Prior to this fix, is was possible for the parent parser to be
garbage-collected too early.
Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com> Co-authored-by: Gregory P. Smith <greg@krypto.org> Co-authored-by: Stan Ulbrych <stanulbrych@gmail.com>
[3.12] gh-135661: Fix CDATA section parsing in HTMLParser (GH-135665) (#137774)
"] ]>" and "]] >" no longer end the CDATA section.
Make CDATA section parsing context depending.
Add private method HTMLParser._set_support_cdata() to change the context.
If called with True, "<[CDATA[" starts a CDATA section which ends with "]]>".
If called with False, "<[CDATA[" starts a bogus comments which ends with ">".
(cherry picked from commit 0cbbfc462119b9107b373c24d2bda5a1271bed36)
[3.12] gh-135661: Fix parsing start and end tags in HTMLParser according to the HTML5 standard (GH-135930) (GH-136268)
* Whitespaces no longer accepted between `</` and the tag name.
E.g. `</ script>` does not end the script section.
* Vertical tabulation (`\v`) and non-ASCII whitespaces no longer recognized
as whitespaces. The only whitespaces are `\t\n\r\f `.
* Null character (U+0000) no longer ends the tag name.
* Attributes and slashes after the tag name in end tags are now ignored,
instead of terminating after the first `>` in quoted attribute value.
E.g. `</script/foo=">"/>`.
* Multiple slashes and whitespaces between the last attribute and closing `>`
are now ignored in both start and end tags. E.g. `<a foo=bar/ //>`.
* Multiple `=` between attribute name and value are no longer collapsed.
E.g. `<a foo==bar>` produces attribute "foo" with value "=bar".
* Whitespaces between the `=` separator and attribute name or value are no
longer ignored. E.g. `<a foo =bar>` produces two attributes "foo" and
"=bar", both with value None; `<a foo= bar>` produces two attributes:
"foo" with value "" and "bar" with value None.
* Fix data loss after unclosed script or style tag (gh-86155).
Also backport test.support.subTests() (gh-135120).
[3.12] gh-135462: Fix quadratic complexity in processing special input in HTMLParser (GH-135464) (GH-135483)
End-of-file errors are now handled according to the HTML5 specs --
comments and declarations are automatically closed, tags are ignored.
(cherry picked from commit 6eb6c5dbfb528bd07d77b60fd71fd05d81d45c41)
[3.12] gh-132415: Use shutil.which() in missing_compiler_executable() (GH-132906) (GH-135392)
Replace deprecated distutils.spawn.find_executable() with
shutil.which() in missing_compiler_executable() of test.support.
(cherry picked from commit de6482eda3a46cc9c9a03fb9ba57295ab99b4722)
Co-authored-by: Victor Stinner <vstinner@python.org>
[3.12] gh-123409: fix `IPv6Address.reverse_pointer` for IPv4-mapped addresses (GH-123419) (GH-135086)
Fix functionality that was broken with better textual representation for IPv4-mapped addresses (gh-87799)
(cherry picked from commit 77a2fb4bf1a1b160d6ce105508288fc77f636943)
[3.12] gh-87799: Improve the textual representation of IPv4-mapped IPv6 addresses (GH-29345) (GH-135081)
Represent IPv4-mapped IPv6 address as x:x:x:x:x:x:d.d.d.d,
where the 'x's are the hexadecimal values
of the six high-order 16-bit pieces of the address,
and the 'd's are the decimal values
of the four low-order 8-bit pieces of the address
(standard IPv4 representation).
Co-authored-by: Seth Michael Larson <seth@python.org> Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com> Co-authored-by: Serhiy Storchaka <storchaka@gmail.com> Co-authored-by: Gregory P. Smith <greg@krypto.org>
Serhiy Storchaka [Mon, 26 May 2025 03:33:22 +0000 (06:33 +0300)]
[3.12] gh-133767: Fix use-after-free in the unicode-escape decoder with an error handler (GH-129648) (GH-133944) (#134337)
If the error handler is used, a new bytes object is created to set as
the object attribute of UnicodeDecodeError, and that bytes object then
replaces the original data. A pointer to the decoded data will became invalid
after destroying that temporary bytes object. So we need other way to return
the first invalid escape from _PyUnicode_DecodeUnicodeEscapeInternal().
_PyBytes_DecodeEscape() does not have such issue, because it does not
use the error handlers registry, but it should be changed for compatibility
with _PyUnicode_DecodeUnicodeEscapeInternal().
(cherry picked from commit 9f69a58623bd01349a18ba0c7a9cb1dad6a51e8e)
(cherry picked from commit 6279eb8c076d89d3739a6edb393e43c7929b429d)
Co-authored-by: Srinivas Reddy Thatiparthy (తాటిపర్తి శ్రీనివాస్ రెడ్డి) <thatiparthysreenivas@gmail.com> Co-authored-by: Eric V. Smith <ericvsmith@users.noreply.github.com>
In GH-115684, HopedForLuck noted that `datetime.date.replace()`
documentation was confusing because it looked like it would be changing
immutable objects.
This documentation change specifies that the `replace()` methods in
`datetime` return new objects. This uses similar wording to the
documentation for `datetime.combine()`, which specifies that a new
datetime is returned. This is also similar to wording for
`string.replace()`, except `string.replace()` emphasizes that a "copy"
is returned.
Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com> Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com> Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Co-authored-by: Sergey B Kirpichev <skirpichev@gmail.com> Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com> Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com> Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com> Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>
[3.12] gh-89039: Call subclass constructors in datetime.*.replace (GH-114780) (GH-131239)
When replace() method is called on a subclass of datetime, date or time,
properly call derived constructor. Previously, only the base class's
constructor was called.
Also, make sure to pass non-zero fold values when creating subclasses in
various methods. Previously, fold was silently ignored.
(cherry picked from commit 46190d9ea8a878a03d95b4e1bdcdc9ed576cf3fa)
Don't pass direct references to sockaddr members since their type may
not match PyArg_ParseTuple() types. Instead, use temporary 'int' and
'unsigned char' variables, and update sockaddr members afterwards.
[3.12] gh-131736: only apply `security_level` workaround in `test_ssl` for security levels greater than 1 (GH-131739) (#131966)
gh-131736: only apply `security_level` workaround in `test_ssl` for security levels greater than 1 (GH-131739)
(cherry picked from commit 3b3720f1a26ab34377542b48eb6a6565f78ff892)
Co-authored-by: Will Childs-Klein <willck93@gmail.com>