Thanks for reporting this bug. I haven't reproduced it, but marked it confirmed bc I see how it could happen.
A simple fix would be to not dereference ts without checking for it to be NULL. The question is whether we should be doing more at console_create to not honor lxc.console during attach. ** Information type changed from Private to Public ** Changed in: lxc (Ubuntu) Status: New => Confirmed -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to lxc in Ubuntu. https://bugs.launchpad.net/bugs/1567037 Title: lxc-attach crashed with SIGSEGV in get_pty_on_host() Status in lxc package in Ubuntu: Confirmed Bug description: Installed unity8-lxc, ran unity8-setup, then rebooted. Login to unity8 lxc session failed (somehow nothing happened), then I logged into Unity7 and the crash happened. ProblemType: Crash DistroRelease: Ubuntu 16.04 Package: lxc1 2.0.0~rc15-0ubuntu1 ProcVersionSignature: Ubuntu 4.4.0-17.33-generic 4.4.6 Uname: Linux 4.4.0-17-generic x86_64 ApportVersion: 2.20.1-0ubuntu1 Architecture: amd64 Date: Wed Apr 6 20:11:34 2016 ExecutablePath: /usr/bin/lxc-attach InstallationDate: Installed on 2015-12-03 (124 days ago) InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Alpha amd64 (20151203) ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-17-generic.efi.signed root=UUID=dccfbc3c-48bc-43ed-9881-36efaa2ef6c5 ro quiet splash vt.handoff=7 SegvAnalysis: Segfault happened at: 0x563ee5318994 <main+884>: movl $0x1,0x1c(%r14) PC (0x563ee5318994) ok source "$0x1" ok destination "0x1c(%r14)" (0x0000001c) not located in a known VMA region (needed writable region)! SegvReason: writing NULL VMA Signal: 11 SourcePackage: lxc Stacktrace: #0 0x0000563ee5318994 in main () No symbol table info available. StacktraceTop: main () ThreadStacktrace: . Thread 1 (Thread 0x7fe20540f840 (LWP 2993)): #0 0x0000563ee5318994 in main () No symbol table info available. Title: lxc-attach crashed with SIGSEGV in main() UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: defaults.conf: lxc.network.type = veth lxc.network.link = lxcbr0 lxc.network.flags = up lxc.network.hwaddr = 00:16:3e:xx:xx:xx To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1567037/+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