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Bug 1696481 - Mark CONFIG_LIBNVDIMM=m to support the NVDIMM security unlock flow
Summary: Mark CONFIG_LIBNVDIMM=m to support the NVDIMM security unlock flow
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel
Version: rawhide
Hardware: x86_64
OS: Linux
Target Milestone: ---
Assignee: Kernel Maintainer List
QA Contact: Fedora Extras Quality Assurance
Depends On:
TreeView+ depends on / blocked
Reported: 2019-04-04 23:49 UTC by Dan Williams
Modified: 2019-04-08 18:09 UTC (History)
19 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Last Closed: 2019-04-08 18:09:38 UTC

Attachments (Terms of Use)

Description Dan Williams 2019-04-04 23:49:27 UTC
1. Please describe the problem:

Historically CONFIG_LIBNVDIMM was marked "=y" because there was at least one NVDIMM provider marked "=y". However, that is no longer the case:


More importantly the CONFIG_LIBNVDIMM=y setting currently defeats the NVDIMM security unlock flow.

The keys required to unlock NVDIMMs are currently loaded via modprobe.conf rule like the following:

install libnvdimm /usr/bin/ndctl load-keys ; /sbin/modprobe --ignore-install libnvdimm $CMDLINE_OPTS

With CONFIG_LIBNVDIMM=y built-in there is no trigger to automate the loading of the keys. For reference the key handling implementation follows that of fscrypt where where a master-key protects the per-NVDIMM key material.

Longer term the CONFIG_NVDIMM_KEYS dependency will be fixed to depend on CONFIG_LIBNVDIMM=m, or otherwise move the specific dependency to its own module.

In the meantime a change to the shipping configuration is needed for pre-v5.2 kernels, and to support CONFIG_NVDIMM_SECURITY=y in post v5.2 kernels.

2. What is the Version-Release number of the kernel:

Latest rawhide:


3. Did it work previously in Fedora? If so, what kernel version did the issue
   *first* appear?  Old kernels are available for download at :

It never worked and the feature was developed on CONFIG_LIBNVDIMM=m builds.

4. Can you reproduce this issue? If so, please provide the steps to reproduce
   the issue below:

There is no trigger to run the "ndctl load-keys" helper prior to the driver attempting to unlock DIMMs.

5. Does this problem occur with the latest Rawhide kernel? To install the
   Rawhide kernel, run ``sudo dnf install fedora-repos-rawhide`` followed by
   ``sudo dnf update --enablerepo=rawhide kernel``:


6. Are you running any modules that not shipped with directly Fedora's kernel?:


7. Please attach the kernel logs. You can get the complete kernel log
   for a boot with ``journalctl --no-hostname -k > dmesg.txt``. If the
   issue occurred on a previous boot, use the journalctl ``-b`` flag.


Comment 1 Jeremy Cline 2019-04-08 18:09:38 UTC
Hi Dan,

CONFIG_LIBNVDIMM=m should arrive in tomorrow's Rawhide build (kernel-5.1.0-0.rc4.git1.1.fc31).

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