HAProxy - Load balancer
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Aurelien DARRAGON 68cfb222b5 BUG/MEDIUM: pattern: prevent UAF on reused pattern expr
Since c5959fd ("MEDIUM: pattern: merge same pattern"), UAF (leading to
crash) can be experienced if the same pattern file (and match method) is
used in two default sections and the first one is not referenced later in
the config. In this case, the first default section will be cleaned up.
However, due to an unhandled case in the above optimization, the original
expr which the second default section relies on is mistakenly freed.

This issue was discovered while trying to reproduce GH #2708. The issue
was particularly tricky to reproduce given the config and sequence
required to make the UAF happen. Hopefully, Github user @asmnek not only
provided useful informations, but since he was able to consistently
trigger the crash in his environment he was able to nail down the crash to
the use of pattern file involved with 2 named default sections. Big thanks
to him.

To fix the issue, let's push the logic from c5959fd a bit further. Instead
of relying on "do_free" variable to know if the expression should be freed
or not (which proved to be insufficient in our case), let's switch to a
simple refcounting logic. This way, no matter who owns the expression, the
last one attempting to free it will be responsible for freeing it.
Refcount is implemented using a 32bit value which fills a previous 4 bytes
structure gap:

        int                        mflags;               /*    80     4 */

        /* XXX 4 bytes hole, try to pack */

        long unsigned int          lock;                 /*    88     8 */
(output from pahole)

Even though it was not reproduced in 2.6 or below by @asmnek (the bug was
revealed thanks to another bugfix), this issue theorically affects all
stable versions (up to c5959fd), thus it should be backported to all
stable versions.
2024-09-09 16:07:05 +02:00
.github CI: QUIC Interop: use different artifact names for uploading logs 2024-08-26 11:19:41 +02:00
addons MINOR: startup: rename readcfgfile in parse_cfg 2024-08-07 18:41:41 +02:00
admin CLEANUP: assorted typo fixes in the code and comments 2024-09-03 17:49:21 +02:00
dev DEV: patchbot: detect commit IDs starting with 7 chars 2024-09-04 09:41:40 +02:00
doc DOC: configuration: place the HAPROXY_HTTP_LOG_FMT example on the correct line 2024-09-06 07:41:16 +02:00
examples MEDIUM: protocol: add MPTCP per address support 2024-08-30 18:53:49 +02:00
include BUG/MEDIUM: pattern: prevent UAF on reused pattern expr 2024-09-09 16:07:05 +02:00
reg-tests REGTESTS: h1/h2: Update script testing H1/H2 protocol upgrades 2024-09-06 14:18:02 +02:00
scripts SCRIPTS: create-release: no more need to skip architecture.txt 2024-07-10 15:38:45 +02:00
src BUG/MEDIUM: pattern: prevent UAF on reused pattern expr 2024-09-09 16:07:05 +02:00
tests MAJOR: import: update mt_list to support exponential back-off (try #2) 2024-07-09 16:46:38 +02:00
.cirrus.yml CI: FreeBSD: upgrade image, packages 2024-06-04 11:19:00 +02:00
.gitattributes MINOR: Configure the cpp userdiff driver for *.[ch] in .gitattributes 2021-02-22 18:17:57 +01:00
.gitignore CONTRIB: Add vi file extensions to .gitignore 2023-06-02 18:14:34 +02:00
.mailmap DOC: update Tim's address in .mailmap 2021-09-16 09:14:14 +02:00
.travis.yml CI: travis-ci: temporarily disable arm64 builds 2021-08-07 07:28:15 +02:00
BRANCHES DOC: fix some spelling issues over multiple files 2021-01-08 14:53:47 +01:00
BSDmakefile BUILD: makefile: commit the tiny FreeBSD makefile stub 2023-05-24 17:17:36 +02:00
CHANGELOG [RELEASE] Released version 3.1-dev7 2024-09-05 18:53:54 +02:00
CONTRIBUTING CLEANUP: assorted typo fixes in the code and comments 2021-08-16 12:37:59 +02:00
INSTALL DOC: install: don't reference removed CPU arg 2024-07-16 20:06:06 +02:00
LICENSE LICENSE: add licence exception for OpenSSL 2012-09-07 13:52:26 +02:00
MAINTAINERS MAJOR: spoe: Let the SPOE back into the game 2024-05-22 09:04:38 +02:00
Makefile MINOR: quic: Token for future connections implementation. 2024-08-30 17:04:09 +02:00
README.md DOC: change the link to the FreeBSD CI in README.md 2024-06-03 15:21:29 +02:00
SUBVERS BUILD: use format tags in VERDATE and SUBVERS files 2013-12-10 11:22:49 +01:00
VERDATE [RELEASE] Released version 3.1-dev7 2024-09-05 18:53:54 +02:00
VERSION [RELEASE] Released version 3.1-dev7 2024-09-05 18:53:54 +02:00

HAProxy

alpine/musl AWS-LC openssl no-deprecated Illumos NetBSD FreeBSD VTest

HAProxy logo

HAProxy is a free, very fast and reliable reverse-proxy offering high availability, load balancing, and proxying for TCP and HTTP-based applications.

Installation

The INSTALL file describes how to build HAProxy. A list of packages is also available on the wiki.

Getting help

The discourse and the mailing-list are available for questions or configuration assistance. You can also use the slack or IRC channel. Please don't use the issue tracker for these.

The issue tracker is only for bug reports or feature requests.

Documentation

The HAProxy documentation has been split into a number of different files for ease of use. It is available in text format as well as HTML. The wiki is also meant to replace the old architecture guide.

Please refer to the following files depending on what you're looking for:

  • INSTALL for instructions on how to build and install HAProxy
  • BRANCHES to understand the project's life cycle and what version to use
  • LICENSE for the project's license
  • CONTRIBUTING for the process to follow to submit contributions

The more detailed documentation is located into the doc/ directory:

License

HAProxy is licensed under GPL 2 or any later version, the headers under LGPL 2.1. See the LICENSE file for a more detailed explanation.