From: "Daniel P. Berrange" <berrange@redhat.com> Currently the LXC container tries to skip selinux/securityfs mounts if the directory does not exist in the filesystem, or if SELinux is disabled. The former check is flawed because the /sys/fs/selinux or /sys/kernel/securityfs directories may exist in sysfs even if the mount type is disabled. Instead of just doing an access() check, use an virFileIsMounted() to see if the FS is actually present in the host OS. This also avoids the need to check is_selinux_enabled(). Signed-off-by: Daniel P. Berrange <berrange@redhat.com> --- src/lxc/lxc_container.c | 37 +++++++++++++++++++++++-------------- 1 file changed, 23 insertions(+), 14 deletions(-) diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c index 992930d..9e5a735 100644 --- a/src/lxc/lxc_container.c +++ b/src/lxc/lxc_container.c @@ -756,15 +756,16 @@ typedef struct { const char *type; int mflags; bool skipUserNS; + bool skipUnmounted; } virLXCBasicMountInfo; static const virLXCBasicMountInfo lxcBasicMounts[] = { - { "proc", "/proc", "proc", MS_NOSUID|MS_NOEXEC|MS_NODEV, false }, - { "/proc/sys", "/proc/sys", NULL, MS_BIND|MS_RDONLY, false }, - { "sysfs", "/sys", "sysfs", MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, false }, - { "securityfs", "/sys/kernel/security", "securityfs", MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, true }, + { "proc", "/proc", "proc", MS_NOSUID|MS_NOEXEC|MS_NODEV, false, false }, + { "/proc/sys", "/proc/sys", NULL, MS_BIND|MS_RDONLY, false, false }, + { "sysfs", "/sys", "sysfs", MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, false, false }, + { "securityfs", "/sys/kernel/security", "securityfs", MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, true, true }, #if WITH_SELINUX - { SELINUX_MOUNT, SELINUX_MOUNT, "selinuxfs", MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, true }, + { SELINUX_MOUNT, SELINUX_MOUNT, "selinuxfs", MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, true, true }, #endif }; @@ -851,16 +852,24 @@ static int lxcContainerMountBasicFS(bool userns_enabled) VIR_DEBUG("Processing %s -> %s", mnt->src, mnt->dst); - /* Skip if mount doesn't exist in source */ - if ((mnt->src[0] == '/') && - (access(mnt->src, R_OK) < 0)) - continue; + if (mnt->skipUnmounted) { + char *hostdir; + int ret; -#if WITH_SELINUX - if (STREQ(mnt->src, SELINUX_MOUNT) && - !is_selinux_enabled()) - continue; -#endif + if (virAsprintf(&hostdir, "/.oldroot%s", mnt->dst) < 0) + goto cleanup; + + ret = virFileIsMountPoint(hostdir); + VIR_FREE(hostdir); + if (ret < 0) + goto cleanup; + + if (ret == 0) { + VIR_DEBUG("Skipping '%s' which isn't mounted in host", + mnt->dst); + continue; + } + } if (mnt->skipUserNS && userns_enabled) { VIR_DEBUG("Skipping due to user ns enablement"); -- 1.8.3.1