[systemd-devel] systemd kills user process (apache) when logout by sftp is initiated

[Mantas Mikulėnas]

On Thu, Feb 1, 2018 at 1:32 PM, Simon Becks <beckssimon5 at gmail.com> wrote:

> Is this an expected behavior?
>
> Debian 9 with systemd 232-25+deb9u1
>
> Apache is running as user wp_user.
>
> After logging in and logging out via sftp as user wp_user - systemd
> kills apache process.
>
> Feb  1 10:58:25 shop systemd: pam_unix(systemd-user:session): session
> opened for user wp_user by (uid=0)
> Feb  1 11:01:58 shop sshd[23747]: Connection closed by client-ip port
> 38409 [preauth]
> Feb  1 11:07:36 shop sshd[23673]: Received disconnect from client-ip2
> port 53274:11:
> Feb  1 11:07:36 shop sshd[23673]: Disconnected from client-ip2 port 53274
> Feb  1 11:07:36 shop sshd[23664]: pam_unix(sshd:session): session
> closed for user wp_user
> Feb  1 11:07:36 shop systemd-logind[480]: Removed session 3177.
> Feb  1 11:07:36 shop systemd: pam_unix(systemd-user:session): session
> closed for user wp_user
>
> [Thu Feb 01 11:07:36.170606 2018] [mpm_prefork:emerg] [pid 20396]
> (43)Identifier removed: AH00144: couldn't grab the accept mutex
> [Thu Feb 01 11:07:36.170606 2018] [mpm_prefork:emerg] [pid 20910]
> (43)Identifier removed: AH00144: couldn't grab the accept mutex
> [Thu Feb 01 11:07:36.170624 2018] [mpm_prefork:emerg] [pid 20394]
> (43)Identifier removed: AH00144: couldn't grab the accept mutex
> [Thu Feb 01 11:07:36.170625 2018] [mpm_prefork:emerg] [pid 20393]
> (43)Identifier removed: AH00144: couldn't grab the accept mutex
> [Thu Feb 01 11:07:36.170625 2018] [mpm_prefork:emerg] [pid 20408]
> (43)Identifier removed: AH00144: couldn't grab the accept mutex
> [Thu Feb 01 11:07:36.175260 2018] [mpm_prefork:emerg] [pid 20407]
> (43)Identifier removed: AH00144: couldn't grab the accept mutex
> [Thu Feb 01 11:07:36.218866 2018] [core:alert] [pid 20375] AH00050:
> Child 20393 returned a Fatal error... Apache is exiting!
> [Thu Feb 01 11:07:36.218914 2018] [:emerg] [pid 20375] AH02818: MPM
> run failed, exiting
>

For users outside the "system account" UID range (usually 1–999), a logout
will cause systemd to clean up remaining "junk" such as SysV IPC resources.
(Those are unusual in that the OS doesn't automatically remove them after
the last process exits, unlike e.g. regular sockets...)

If you must give high UIDs to service accounts, set RemoveIPC=no in your
logind.conf.

-- 
Mantas Mikulėnas
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