[Samba] Memory Leak in rpcd_spoolss?

[Jeremy Allison]

On Tue, Sep 20, 2022 at 09:35:21PM +0200, Wilko Meyer via samba wrote:
>Hi,
>
>I may've observed a memory leak condition affecting the rpcd_spoolss processes, leading them to cause
>OOM-Events on one of the systems I maintain.
>
>The used Samba version is 4.16.1 (4.16.1+dfsg-8~bpo11+1) and the Kernel version is 4.19.0-17-amd64.
>
>~ # awk '/oom_reaper/' /var/log/syslog |  grep -o -P '(?<=\().*(?=\))' | sort | uniq -c
>     28 rpcd_spoolss
>
>So far there have been 28 OOM-Events in total where the rpcd_spoolss process got terminated by the oom_reaper.
>
>As processes being terminated by the oom_reaper doesn't necessarily have to be the processes causing the
>OOM situation, I cross-checked this observation by evaluation the top 3 processes consuming most resident
>memory using atopsar.
>
>I choose a timeframe between the last two OOM-Events (which were about 2h apart) as we only store atop
>metrics in a 10m interval, which would've been too narrow (mostly less than 10-20m between each
>OOM-Event for the other Events) to observe the  steadily increase in memory allocation throughout
>the day:

Looks like Metze has discovered the root cause of this.

https://bugzilla.samba.org/show_bug.cgi?id=15201

Hope this helps !