On Wed, Mar 21, 2018 at 3:03 PM, Jamie Strandboge <jamie@canonical.com> wrote:

On Wed, 2018-03-21 at 13:10 +0100, Christian Ehrhardt wrote:
> d8116b5a "security: Introduce functions for input device hot(un)plug"
> implemented the code (Set|Restore)InputLabel for several security
> modules,
> this patch adds an AppArmor implementation for it as well.
>
> That fixes hot-plugging event input devices by generating a rule for
> the
> path that needs to be accessed.
>
> Example hot adding:
>   <input type='passthrough' bus='virtio'>
>      <source evdev='/dev/input/event0' />
>   </input>
> Creates now:
>   "/dev/input/event0" rwk,
>
> Fixes: https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1755153
>
> Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
> ---
>  src/security/security_apparmor.c | 45
> ++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 45 insertions(+)
>
> diff --git a/src/security/security_apparmor.c
> b/src/security/security_apparmor.c
> index 7509552..3be8eeb 100644
> --- a/src/security/security_apparmor.c
> +++ b/src/security/security_apparmor.c
> @@ -758,6 +758,48 @@ AppArmorRestoreMemoryLabel(virSecurityManagerPtr
> mgr,
>
>  /* Called when hotplugging */
>  static int
> +AppArmorSetInputLabel(virSecurityManagerPtr mgr,
> +                      virDomainDefPtr def,
> +                      virDomainInputDefPtr input)
> +{
> +    switch ((virDomainInputType) input->type) {
> +    case VIR_DOMAIN_INPUT_TYPE_PASSTHROUGH:
> +        if (!virFileExists(input->source.evdev)) {

Check if input->type and input->source are NULL?

Yes, good idea for defensive coding 

> +            virReportError(VIR_ERR_INTERNAL_ERROR,
> +                           _("%s: \'%s\' does not exist"),
> +                           __func__, input->source.evdev);
> +            return -1;
> +        }
> +        return reload_profile(mgr, def, input->source.evdev, true);
> +        break;
> +
> +    case VIR_DOMAIN_INPUT_TYPE_MOUSE:
> +    case VIR_DOMAIN_INPUT_TYPE_TABLET:
> +    case VIR_DOMAIN_INPUT_TYPE_KBD:
> +    case VIR_DOMAIN_INPUT_TYPE_LAST:
> +        break;
> +    }
> +
> +    return 0;
> +}
> +
> +
> +static int
> +AppArmorRestoreInputLabel(virSecurityManagerPtr mgr,
> +                          virDomainDefPtr def,
> +                          virDomainInputDefPtr input
> ATTRIBUTE_UNUSED)
> +{
> +    virSecurityLabelDefPtr secdef =
> +        virDomainDefGetSecurityLabelDef(def,
> SECURITY_APPARMOR_NAME);
> +
> +    if (!secdef || !secdef->relabel)
> +        return 0;
> +

secdef unneeded due to reload_profile.

Thanks, I found why I wondered (being sure I have dropped them).

I only dropped it on the "Set" functions before.

Next version will have it dropped on "Restore" as well.

 

> +    return reload_profile(mgr, def, NULL, false);
> +}
> +
> +/* Called when hotplugging */
> +static int
>  AppArmorSetSecurityImageLabel(virSecurityManagerPtr mgr,
>                                virDomainDefPtr def,
>                                virStorageSourcePtr src)
> @@ -1158,6 +1200,9 @@ virSecurityDriver virAppArmorSecurityDriver = {
>      .domainSetSecurityMemoryLabel       = AppArmorSetMemoryLabel,
>      .domainRestoreSecurityMemoryLabel   =
> AppArmorRestoreMemoryLabel,
>
> +    .domainSetSecurityInputLabel        = AppArmorSetInputLabel,
> +    .domainRestoreSecurityInputLabel    = AppArmorRestoreInputLabel,
> +
>      .domainSetSecurityDaemonSocketLabel =
> AppArmorSetSecurityDaemonSocketLabel,
>      .domainSetSecuritySocketLabel       =
> AppArmorSetSecuritySocketLabel,
>      .domainClearSecuritySocketLabel     =
> AppArmorClearSecuritySocketLabel,
--

Jamie Strandboge             | http://www.canonical.com

--

Christian Ehrhardt

Software Engineer, Ubuntu Server

Canonical Ltd