Re: [libvirt] This patch adds the label to lxc-enter-namespace

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 (Resend to the correct list) lxc-enter-namespace allows a process from outside a container to start a process inside a container. One problem with the current code is the process running within the container would run with the label of the process that created it. For example if the admin process is running as unconfined_t and executes the following command # virsh -c lxc:/// lxc-enter-namespace --nolabel dan -- /bin/ps -eZ LABEL PID TTY TIME CMD system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 1 pts/0 00:00:00 systemd system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 3 pts/1 00:00:00 sh system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 24 ? 00:00:00 systemd-journal system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 29 ? 00:00:00 dhclient staff_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 47 ? 00:00:00 ps Note the ps command is running as unconfined_t, After this patch, virsh -c lxc:/// lxc-enter-namespace dan -- /bin/ps -eZ LABEL PID TTY TIME CMD system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 1 pts/0 00:00:00 systemd system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 3 pts/1 00:00:00 sh system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 24 ? 00:00:00 systemd-journal system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 32 ? 00:00:00 dhclient system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 38 ? 00:00:00 ps I also add a --nolabel command to virsh, which can go back to the original behaviour. virsh -c lxc:/// lxc-enter-namespace --nolabel dan -- /bin/ps -eZ LABEL PID TTY TIME CMD system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 1 pts/0 00:00:00 systemd system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 3 pts/1 00:00:00 sh system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 24 ? 00:00:00 systemd-journal system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 32 ? 00:00:00 dhclient staff_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 37 ? 00:00:00 ps One problem I had when I originally did the patch is lxcDomainGetSecurityLabel was returning the incorrect label, I needed the label of the initpid within the container not its parent process, so I changed this function to match OpenNamespaces function. One last strangeness, about half the time I run this, virsh hangs and never returns. Seems like if (conn->driver->domainGetSecurityLabel(domain, seclabel) == 0) { Gets hung up. I have attached the strace in out1.gz

@@ -7719,13 +7721,17 @@ cmdLxcEnterNamespace(vshControl *ctl, const vshCmd *cmd) */ if (virFork(&pid) < 0) goto cleanup; + + if (!vshCommandOptBool(cmd, "nolabel")) + flags |= SECURITY_LABEL; + if (pid == 0) {

if (virDomainLxcEnterNamespace(dom, nfdlist, fdlist, NULL, NULL, - 0) < 0) + flags) < 0) _exit(255); /* Fork a second time because entering the