error after resetting servers and trying to add new ones

[Wojtek]

I'm using PHP memcached extension (master branch of git://github.com/php-memcached-dev/php-memcached.git) . When compiled with 1.0.15 and resetting servers list and reading new servers works fine, but when compiled with 1.0.16 PHP dies without errors or stack trace :(

resetServers uses:
memcached_servers_reset(m_obj->memc);

addServers uses:
memcached_server_list_append_with_weight(list, host, port, weight, &status);
memcached_server_push(m_obj->memc, list);
memcached_server_list_free(list);

I didn't have time to debug any further ... sorry

[Wojtek (woledzki)]

Just to add some more - I'm using persistent memcached connenction

[Brian Aker (brianaker)]

Thanks, I am looking into this.

[Timon (timosha-l)]

test for this issue

[Adam Saponara (as-v)]

Fix + test for this issue attached

[Timon (timosha-l)]

cool, latest patch works fine for 1.0.18, tested in production

[Mattsch (mattsch)]

=dev-libs/libmemcached-1.0.18-r2 segfaults with the OPT_LIBKETAMA_COMPATIBLE enabled and a call to addServer, then resetServerList and another call to addServer.

Reproducible: Always

Steps to Reproduce:
Example of how to reproduce in php (using pecl-memcached):

<?php
$host = 'localhost';
$port = '11211';
$weight = null;
$m = new Memcached('test');
$m->setOption(Memcached::OPT_LIBKETAMA_COMPATIBLE, true);

var_dump($m->addServer($host, $port, $weight));
var_dump($m->resetServerList());
var_dump($m->addServer($host, $port, $weight));
var_dump($m->getServerList());
?>

Actual Results:
segfault

Expected Results:
A call to addServer after resetServerList should not cause a segfault

[Mattsch (mattsch)]

Created attachment 400200
libmemcached-1.0.18-patch-continuum.patch

Patch from the launchpad bug report.

[Bircoph-4 (bircoph-4)]

Please upload your emerge --info.

[Mattsch (mattsch)]

emerge --info
Portage 2.2.17 (python 3.4.1-final-0, default/linux/amd64/13.0, gcc-4.8.4, glibc-2.20-r2, 3.19.3-gentoo x86_64)
=================================================================
System uname: Linux-3.19.3-gentoo-x86_64-Intel-R-_Core-TM-_i7-4700MQ_CPU_@_2.40GHz-with-gentoo-2.2
KiB Mem: 16365672 total, 14532780 free
KiB Swap: 0 total, 0 free
Timestamp of repository gentoo: Thu, 02 Apr 2015 14:15:01 +0000
sh dash 0.5.7.4
ld GNU ld (Gentoo 2.24 p1.4) 2.24
app-shells/bash: 4.2_p53::gentoo
dev-java/java-config: 2.2.0::gentoo
dev-lang/perl: 5.20.1-r4::gentoo
dev-lang/python: 2.7.9-r1::gentoo, 3.4.1::gentoo
dev-util/cmake: 2.8.12.2-r1::gentoo
dev-util/pkgconfig: 0.28-r1::gentoo
sys-apps/baselayout: 2.2::gentoo
sys-apps/openrc: 0.13.11::gentoo
sys-apps/sandbox: 2.6-r1::gentoo
sys-devel/autoconf: 2.13::gentoo, 2.69::gentoo
sys-devel/automake: 1.11.6-r1::gentoo, 1.13.4::gentoo
sys-devel/binutils: 2.24-r3::gentoo
sys-devel/gcc: 4.8.4::gentoo
sys-devel/gcc-config: 1.7.3::gentoo
sys-devel/libtool: 2.4.6::gentoo
sys-devel/make: 4.1-r1::gentoo
sys-kernel/linux-headers: 3.18::gentoo (virtual/os-headers)
sys-libs/glibc: 2.20-r2::gentoo
Repositories:
                                                                                                                                                                                                    ...

[Matthew Thode (prometheanfire)]

fixed in 1.0.18-r3

[Matthew Thode (prometheanfire)]

works for us as well

[Ryan Gordon (ryan-5)]

Would it be possible to apply this patch to mainline libmemcached in a 1.0.19 release? This is affecting us too, running CentOS 7.