On Wed, May 13, 2020 at 05:20:14PM -0400, Mimi Zohar wrote:
On Wed, 2020-05-13 at 12:41 -0700, Scott Branden wrote:
On 2020-05-13 12:39 p.m., Mimi Zohar wrote:
On Wed, 2020-05-13 at 12:18 -0700, Scott Branden wrote:
On 2020-05-13 12:03 p.m., Mimi Zohar wrote:
On Wed, 2020-05-13 at 11:53 -0700, Scott Branden wrote:
Even if the kernel successfully verified the firmware file signature it would just be wasting its time. The kernel in these use cases is not always trusted. The device needs to authenticate the firmware image itself.
There are also environments where the kernel is trusted and limits the firmware being provided to the device to one which they signed.
The device firmware is being downloaded piecemeal from somewhere and won't be measured?
It doesn't need to be measured for current driver needs.
Sure the device doesn't need the kernel measuring the firmware, but hardened environments do measure firmware.
If someone has such need the infrastructure could be added to the kernel at a later date. Existing functionality is not broken in any way by this patch series.
Wow! You're saying that your patch set takes precedence over the existing expectations and can break them.
Huh? I said existing functionality is NOT broken by this patch series.
Assuming a system is configured to measure and appraise firmware (rules below), with this change the firmware file will not be properly measured and will fail signature verification.
Sample IMA policy rules: measure func=FIRMWARE_CHECK appraise func=FIRMWARE_CHECK appraise_type=imasig
Would a pre and post lsm hook for pread do it?
Luis