[libvirt] [PATCH] Ensure we always setup a private mount namespace for LXC controller

From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; The code for setting up a private /dev/pts for the containers is also responsible for making the LXC controller have a private mount namespace. Unfortunately the /dev/pts code is not run if launching a container without a custom root. This causes the LXC FUSE mount to leak into the host FS. --- src/lxc/lxc_controller.c | 38 ++++++++++++++++++++++++++------------ 1 file changed, 26 insertions(+), 12 deletions(-) diff --git a/src/lxc/lxc_controller.c b/src/lxc/lxc_controller.c index c9d96b3..a1c264c 100644 --- a/src/lxc/lxc_controller.c +++ b/src/lxc/lxc_controller.c @@ -1143,6 +1143,29 @@ cleanup: static int +virLXCControllerSetupPrivateNS(void) +{ + int ret = -1; + + if (unshare(CLONE_NEWNS) < 0) { + virReportSystemError(errno, "%s", + _("Cannot unshare mount namespace")); + goto cleanup; + } + + if (mount("", "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) { + virReportSystemError(errno, "%s", + _("Failed to switch root mount into slave mode")); + goto cleanup; + } + + ret = 0; +cleanup: + return ret; +} + + +static int virLXCControllerSetupDevPTS(virLXCControllerPtr ctrl) { virDomainFSDefPtr root = virDomainGetRootFilesystem(ctrl->def); @@ -1193,18 +1216,6 @@ virLXCControllerSetupDevPTS(virLXCControllerPtr ctrl) goto cleanup; } - if (unshare(CLONE_NEWNS) < 0) { - virReportSystemError(errno, "%s", - _("Cannot unshare mount namespace")); - goto cleanup; - } - - if (mount("", "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) { - virReportSystemError(errno, "%s", - _("Failed to switch root mount into slave mode")); - goto cleanup; - } - if (virAsprintf(&devpts, "%s/dev/pts", root->src) < 0 || virAsprintf(&ctrl->devptmx, "%s/dev/pts/ptmx", root->src) < 0) { virReportOOMError(); @@ -1408,6 +1419,9 @@ virLXCControllerRun(virLXCControllerPtr ctrl) goto cleanup; } + if (virLXCControllerSetupPrivateNS() < 0) + goto cleanup; + if (virLXCControllerSetupLoopDevices(ctrl) < 0) goto cleanup; -- 1.8.0.1