[PATCH v2 00/14] vboot: Fix forged-configuration vulnerability

[Tom Rini]

On Mon, Mar 30, 2020 at 05:11:38PM -0600, Simon Glass wrote:
> Hi,
> 
> On Wed, 18 Mar 2020 at 11:44, Simon Glass <sjg at chromium.org> wrote:
> >
> > When booting a FIT, if 'bootm' is used without a specified configuration,
> > U-Boot will use the default one provided in the FIT. But it does not
> > actually check that the signature is for that configuration.
> >
> > This means that it is possible to duplicate a configuration conf-1 to
> > produce conf-2 (with all the signatures intact), set the default
> > configuration to conf-2 and then boot the image. U-Boot will verify conf-2
> > (in fact since hashed-nodes specifies the conf-1 nodes it will effectively
> > verify conf-1). Then it will happily boot conf-2 even though it might have
> > a different kernel.
> >
> > This series corrects this problem and adds a test to verify it. It also
> > updates fit_check_sign to allow the configuration to be specified.
> >
> > This vulnerability was found by Dmitry Janushkevich and Andrea Barisani of
> > F-Secure, who also wrote the vboot_forge script included here.
> >
> > This is CVE-2020-10648
> >
> > Changes in v2:
> > - Bring in new vboot_forge file from the authors
> >
> > Simon Glass (14):
> >   image: Correct comment for fit_conf_get_node()
> >   image: Be a little more verbose when checking signatures
> >   image: Return an error message from fit_config_verify_sig()
> >   test: vboot: Drop unnecessary parameter for fit_check_sign
> >   test: vboot: Add a test for a forged configuration
> >   test: vboot: Parameterise the test
> >   image: Check hash-nodes when checking configurations
> >   image: Load the correct configuration in fit_check_sign
> >   fit_check_sign: Allow selecting the configuration to verify
> >   test: vboot: Tidy up the code a little
> >   test: vboot: Fix pylint errors
> >   image: Use constants for 'required' and 'key-name-hint'
> >   test: vboot: Move key creation into a function
> >   test: vboot: Reduce fake kernel size to 500 bytes
> >
> >  common/bootm.c               |   6 +-
> >  common/image-cipher.c        |   2 +-
> >  common/image-fit.c           |  26 +--
> >  common/image-sig.c           |  49 +++-
> >  include/image.h              |  24 +-
> >  lib/rsa/rsa-sign.c           |   6 +-
> >  test/py/tests/test_vboot.py  | 155 +++++++------
> >  test/py/tests/vboot_forge.py | 423 +++++++++++++++++++++++++++++++++++
> >  tools/fdt_host.h             |   3 +-
> >  tools/fit_check_sign.c       |   8 +-
> >  tools/image-host.c           |  17 +-
> >  11 files changed, 601 insertions(+), 118 deletions(-)
> >  create mode 100644 test/py/tests/vboot_forge.py
> 
> This is applied to dm/master.
> 
> Tom, shall I send a pull request?


Yes please, thanks!

-- 
Tom
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