Re: [PATCH 1/7] fs: introduce kernel_pread_file* support

[Scott Branden]

Hi Takashi

On 2019-08-23 5:29 a.m., Takashi Iwai wrote:
> On Thu, 22 Aug 2019 21:24:45 +0200,
> Scott Branden wrote:
> > Add kernel_pread_file* support to kernel to allow for partial read
> > of files with an offset into the file.  Existing kernel_read_file
> > functions call new kernel_pread_file functions with offset=0 and
> > flags=KERNEL_PREAD_FLAG_WHOLE.
> Would this change passes the security check like ima?
> I thought security_kernel_post_read_file() checks the whole content
> for calculating the hash...

It passes the fw_run_tests.sh. How do you test the firmware loader 
passes this security check?


What exactly does this ima do? How do you enable/disable using it?

Any reasonable device would check the integrity of the firmware image 
being loaded to it.

And, if part of a security model, authenticate the image.

Whatever security check you are referring to is not needed by 
request_firmware_into_buf when loading

a partial file into a buffer.


> thanks,
>
> Takashi