Re: [PATCH v2] efifb: prevent null-deref when iterating dmi_list

Hi

On Fri, Nov 1, 2013 at 12:10 PM, Jean-Christophe PLAGNIOL-VILLARD
[off-list ref] wrote:

On 17:17 Thu 31 Oct     , David Herrmann wrote:

quoted

Hi

On Thu, Oct 31, 2013 at 11:45 AM, Jean-Christophe PLAGNIOL-VILLARD
[off-list ref] wrote:

quoted

On 18:40 Wed 02 Oct     , David Herrmann wrote:

quoted

The dmi_list array is initialized using gnu designated initializers, and
therefore may contain fewer explicitly defined entries as there are
elements in it. This is because the enum above with M_xyz constants
contains more items than the designated initializer. Those elements not
explicitly initialized are implicitly set to 0.

Now efifb_setup() loops through all these array elements, and performs
a strcmp on each item. For non explicitly initialized elements this will
be a null pointer:

This patch swaps the check order in the if statement, thus checks first
whether dmi_list[i].base is null.

Signed-off-by: James Bates <redacted>
Signed-off-by: David Herrmann <redacted>

with the simpleDRM arriving next merge I'm wondering if we need to keep it?

SimpleDRM is not coming next merge-window. It's basically finished,
but I'm still working on the user-space side as its KMS api is highly
reduced compared to fully-featured DRM/KMS drivers. Maybe 3.13 will
work out.

do you have a git tree for the simpleDRM that I can pull?

Sure, I usually push it to my fdo tree:
  http://cgit.freedesktop.org/~dvdhrm/linux/log/?h=simpledrm
But note that you shouldn't be using it right now. User-space fails on
it as SimpleDRM only provides a single KMS-FB. It also needs to be
adjusted to the new x86-sysfb changes and I am reworking the handover
to real drivers.

Cheers
David