[libvirt] [PATCH] qemu: Don't assume secret provided for LUKS encryption

[Ján Tomko]

On Thu, Dec 22, 2016 at 09:12:43AM -0500, John Ferlan wrote:
>https://bugzilla.redhat.com/show_bug.cgi?id=1405269
>
>If a secret was not provided for what was determined to be a LUKS
>encrypted disk (during virStorageFileGetMetadata processing when
>called from qemuDomainDetermineDiskChain as a result of hotplug
>attach qemuDomainAttachDeviceDiskLive), then do not attempt to
>look it up (avoiding a libvirtd crash) and do not alter the format
>to "luks" when adding the disk; otherwise, the device_add would
>fail with a message such as:
>
>   "unable to execute QEMU command 'device_add': Property 'scsi-hd.drive'
>    can't find value 'drive-scsi0-0-0-0'"
>
>because of assumptions that when the format=luks that libvirt would have
>provided the secret to decrypt the volume.
>
>Access to unlock the volume will thus be left to the application.
>
>Signed-off-by: John Ferlan <jferlan at redhat.com>
>---
>
> I could have spread things over 2 patches (one to create the helper
> and one to add the extra check for nsecrets > 0), but just going with
> one to fix the issue just felt cleaner (besides makes any possible
> backports a bit simpler).
>
> NB: The "extra" !virStorageSourceIsEmpty check for the qemu_command
>     path is a no-op essentially.
>
> src/qemu/qemu_command.c |  3 +--
> src/qemu/qemu_domain.c  | 15 +++++++++++++--
> src/qemu/qemu_domain.h  |  3 +++
> src/qemu/qemu_hotplug.c |  3 ++-
> 4 files changed, 19 insertions(+), 5 deletions(-)
>

ACK

>diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
>index 92a2e73..6b10e63 100644
>--- a/src/qemu/qemu_hotplug.c
>+++ b/src/qemu/qemu_hotplug.c
>@@ -3584,7 +3584,8 @@ qemuDomainRemoveDiskDevice(virQEMUDriverPtr driver,
>      * can remove the luks object password too
>      */
>     if (!virStorageSourceIsEmpty(disk->src) && disk->src->encryption &&
>-        disk->src->encryption->format == VIR_STORAGE_ENCRYPTION_FORMAT_LUKS) {
>+        disk->src->encryption->format == VIR_STORAGE_ENCRYPTION_FORMAT_LUKS &&
>+        disk->src->encryption->nsecrets > 0) {

Why doesn't this code also use the helper?

Jan
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: Digital signature
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20170102/cc313e71/attachment-0001.sig>