Arch Linux

oeut1341

Member

Registered: 2016-06-09

Posts: 26

"No such process" error with pam_systemd, no logind session created

I'm getting a "No such process" error from pam_systemd when logging in (see logs below). This happens with any user, and independently from logging in on the virtual console or sddm.

Login succeeds nonetheless (since pam_systemd is marked as "optional" in the pam.d configuration), but no session is created, XDG_RUNTIME_DIR is not set, etc.

Logs (here when trying to log as root in the virtual console; "debug=yes" set in the pam_systemd config):

Apr 26 12:20:44 mypc login[55532]: pam_unix(login:session): session opened for user root by LOGIN(uid=0)                                                
Apr 26 12:20:44 mypc login[55532]: pam_systemd(login:session): pam-systemd initializing                                                                 
Apr 26 12:20:44 mypc login[55532]: pam_systemd(login:session): Asking logind to create session: uid=0 pid=55532 service=login type=tty class=user desktop= seat= vtnr=0 tty=tty2 display= remote=no remote_user= remote_host=           
Apr 26 12:20:44 mypc login[55532]: pam_systemd(login:session): Failed to create session: No such process

I'm currently stuck trying to debug this. From the error I assume pam_systemd tries to start a non-existent binary, script or similar. How can I find out exactly which process cannot be started?

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 23,192

Re: "No such process" error with pam_systemd, no logind session created

Have you gone through the relevant files as mentioned in the latest news announcment? https://www.archlinux.org/news/glibc-22 … ervention/

oeut1341

Member

Registered: 2016-06-09

Posts: 26

Re: "No such process" error with pam_systemd, no logind session created

grep -r pam_unix2 /etc/pam.d
grep -r pam_unix_ /etc/pam.d

Both commands produce no matches.

loqs

Member

Registered: 2014-03-06

Posts: 18,037

Re: "No such process" error with pam_systemd, no logind session created

Does the system use hidepid?

oeut1341

Member

Registered: 2016-06-09

Posts: 26

Re: "No such process" error with pam_systemd, no logind session created

Does the system use hidepid?

Bingo 

Following advice in https://wiki.archlinux.org/index.php/security#hidepid solves it. Thanks!