Re: [PATCH v2] efifb: prevent null-deref when iterating dmi_list
From: Jean-Christophe PLAGNIOL-VILLARD
Date: Fri Nov 01 2013 - 07:46:23 EST
On 17:17 Thu 31 Oct , David Herrmann wrote:
> Hi
>
> On Thu, Oct 31, 2013 at 11:45 AM, Jean-Christophe PLAGNIOL-VILLARD
> <plagnioj@xxxxxxxxxxxx> wrote:
> > On 18:40 Wed 02 Oct , David Herrmann wrote:
> >> 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 <james.h.bates@xxxxxxxxx>
> >> Signed-off-by: David Herrmann <dh.herrmann@xxxxxxxxx>
> >
> > 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?
>
> Anyhow, this patch is still needed as it fixes a serious bug for simplefb.
ok
>
> Thanks
> David
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