The kernel-module-load interface

kernel-module-load provides the ability to load, or deny loading, specific kernel modules. This interface gives privileged access to the device.

See also the kernel-module-control interface for inserting, removing and querying kernel modules.

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Developer details

Auto-connect: no
Super-privileged: yes

Attributes:

• name (plug, required): provides the name of the kernel module to be loaded (eg, ‘name: pcspkr’)
• load (plug): string to declare when, or whether, to load this module. Values can be one of the following:
  • on-boot (default): loads the kernel module at boot time (eg. load: on-boot)
  • denied: prevents the module from being loaded at all (eg. load: denied). Also known as denylisting in the Linux kernel.
• options (plug): string of options to use when loading the module (eg, options: p1=3 p2=true p3)

In addition to the name attribute being required, either options or load must also be specified.

Consumers of this interface require a snap declaration for distribution via the Snap Store.

Requires snapd version 2.54+.

Code examples

The following is an example snippet for an application snap to load the module foo with options param=2, and to deny loading the module bar:

plugs:
  load-foo:
    interface: kernel-module-load
    modules:
    - name: foo
      options: param=2
  deny-bar:
    interface: kernel-module-load
    modules:
    - name: bar
      load: denied

The load-foo foo kernel module can be more verbosely by declared with the load attribute, resulting in the same behaviour:

plugs:
  load-foo:
    interface: kernel-module-load
    modules:
    - name: foo
      load: on-boot
      options: param=2

The test code can be found in the snapd repository: https://github.com/snapcore/snapd/blob/master/interfaces/builtin/kernel_module_load.go

The source code for the interface is in the snapd repository:https://github.com/snapcore/snapd/blob/master/interfaces/builtin/kernel_module_load_test.go

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Last updated 2 years ago.