Hello Kevin, I don't want to step on Colin's toes here, but I couldn't sort out anything from the logs or files so far. I've had success before with perf to grab call graph information. The usual process is along the lines of:
- enable the ddebs.ubuntu.com repository to get access to debug symbols: https://wiki.ubuntu.com/Debug%20Symbol%20Packages - install packages openssh-server-dbgsym libc6-dbgsym .. as needed - Record perf results during testing with something like: sudo perf record -e syscalls:sys_enter_socket -R -a --call-graph dwarf sleep 20 - test - Check results with something like: sudo perf script With luck this will spit out the function names of the call chain at the time of the socket() syscall that is being killed (probably alongside a lot of unrelated instances -- it's possible to tune the perf line to narrow it down if necessary). I hope this helps, Thanks -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to openssh in Ubuntu. https://bugs.launchpad.net/bugs/1690485 Title: openssh-server SIGSYS with 'UsePrivilegeSeparation sandbox' Status in openssh package in Ubuntu: New Bug description: The 'sshd' process gets 'authentication failure' and refuses to allow any login. dmesg indicates that the problem is SIGSYS on a call to 'socket' (syscall #41, signal #31). On a hunch, I decided to test whether the problem is related to 'seccomp' and changed /etc/ssh/sshd_config from the default # UsePrivilegeSeparation sandbox to the former standard value UsePrivilegeSeparation yes and logins started to work again. Obviously, I'd like to have the additional protection that sandboxing would give me. ProblemType: Bug DistroRelease: Ubuntu 17.04 Package: openssh-server 1:7.4p1-10 ProcVersionSignature: Ubuntu 4.10.0-20.22-generic 4.10.8 Uname: Linux 4.10.0-20-generic x86_64 ApportVersion: 2.20.4-0ubuntu4 Architecture: amd64 CurrentDesktop: XFCE Date: Fri May 12 21:06:20 2017 InstallationDate: Installed on 2017-04-08 (35 days ago) InstallationMedia: SourcePackage: openssh UpgradeStatus: Upgraded to zesty on 2017-04-24 (19 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/1690485/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
