In fa90a7d3 ("BUG/MINOR: proxy: fix email-alert leak on deinit()"), I
tried to fix email-alert deinit() leak the simple way by leveraging
existing free_email_alert() helper function which was already used for
freeing email alert settings used in a default section.
However, as described in GH #2608, there is a subtelty that makes
free_email_alert() not suitable for use from free_proxy().
Indeed, proxy 'mailers.name' hint shares the same memory space than the
pointer to the corresponding mailers section (once the proxy is resolved,
name hint is replaced by the pointer to the section). However, since both
values share the same space (through union), we have to take care of not
freeing `mailers.name` once init_email_alert() was called on the proxy.
Unfortunately, free_email_alert() isn't protected against that, causing
double free() during deinit when mailers section is referenced from
multiple proxy sections. Since there is no easy fix, and that the leak in
itself isn't a big deal (fa90a7d3 was simply an opportunistic fix rather
than a must-have given that the leak only occurs during deinit and not
during runtime), let's actually revert the fix to restore legacy behavior
and prevent deinit errors.
Thanks to @snetat for having reported the issue on Github as well as
providing relevant infos to pinpoint the bug.
It should be backported everywhere fa90a7d3 was backported.
[ada: for versions prior to 3.0, simply revert the offending commit using
'git revert' as proxy_free_common() first appears in 3.0]
HAProxy
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:
- doc/intro.txt for a quick introduction on HAProxy
- doc/configuration.txt for the configuration's reference manual
- doc/lua.txt for the Lua's reference manual
- doc/SPOE.txt for how to use the SPOE engine
- doc/network-namespaces.txt for how to use network namespaces under Linux
- doc/management.txt for the management guide
- doc/regression-testing.txt for how to use the regression testing suite
- doc/peers.txt for the peers protocol reference
- doc/coding-style.txt for how to adopt HAProxy's coding style
- doc/internals for developer-specific documentation (not all up to date)
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.
