Re: BUG #14835: Postgres crashed

On 09/28/2017 05:46 PM, nicola(dot)contu(at)gmail(dot)com wrote:
> The following bug has been logged on the website:
>
> Bug reference: 14835
> Logged by: Nicola Contu
> Email address: nicola(dot)contu(at)gmail(dot)com
> PostgreSQL version: 9.6.5
> Operating system: Centos 6.9
> Description:
>
> Hello,
> after upgrading to postgres 9.6.5 in the last 3weeks we had the db crashing
> three times for the same reason :
>
> SELECT: double free or corruption (!prev): 0x0000000001f4b440 ***
> ======= Backtrace: =========
> /lib64/libc.so.6[0x3eee675dee]
> /lib64/libc.so.6[0x3eee678c80]
>
>
> ======= Memory map: ========
> 00400000-009ff000 r-xp 00000000 fd:00 6431324
> /usr/local/pgsql9.6.5/bin/postgres

Yes, this seems like a bug, but it's quite unclear if it's in PostgreSQL
or due to a bug in some other library.

Please, make sure next time a core dump is generated, so that you can
inspect it, and generate backtrace for example. You'll probably have to
do this:

1) install debuginfo packages (likely using debuginfo-install)

2) enable core files (you'll probably have to set limits in limits.conf
and set core_pattern), see [1] for details

It might also be useful to know what query was being executed at the
time of the crash - that should be logged into the PostgreSQL log.

[1] http://man7.org/linux/man-pages/man5/core.5.html

regards

--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services