Re: [libvirt] [PATCH 12/14] Avoid unsafe use of /proc/$PID/root in LXC block hostdev hotplug

Rewrite lxcDomainAttachDeviceHostdevStorageLive function to use the virProcessRunInMountNamespace helper. This avoids risk of a malicious guest replacing /dev with a absolute symlink, tricking the driver into changing the host OS filesystem. Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com&gt; --- src/lxc/lxc_driver.c | 64 ++++++++++++++-------------------------------------- 1 file changed, 17 insertions(+), 47 deletions(-)

+ if (virCgroupAllowDevicePath(priv->cgroup, + def->source.caps.u.storage.block, + VIR_CGROUP_DEVICE_RWM) != 0) { virReportError(VIR_ERR_INTERNAL_ERROR, _("cannot allow device %s for domain %s"), def->source.caps.u.storage.block, vm->def->name);

goto cleanup; } + if (lxcDomainAttachDeviceMknod(driver, + 0700 | S_IFBLK, + sb.st_rdev, + vm, + dev, + def->source.caps.u.storage.block) < 0) { + if (virCgroupDenyDevicePath(priv->cgroup, + def->source.caps.u.storage.block, + VIR_CGROUP_DEVICE_RWM) != 0) + VIR_WARN("cannot deny device %s for domain %s", + def->source.caps.u.storage.block, vm->def->name); + goto cleanup;