Re: [S390] cio: kernel stack overflow.

From: Martin Schwidefsky
Date: Wed Aug 30 2006 - 13:37:30 EST


On 8/30/06, David Wagner <daw@xxxxxxxxxxxxxxx> wrote:
Have you checked that in all cases all fields of the struct have
been overwritten? For instance, look at this:

Martin Schwidefsky wrote:
>- chp->dev = (struct device) {
>- .parent = &css[0]->device,
>- .release = chp_release,
>- };
>+ chp->dev.parent = &css[0]->device;
>+ chp->dev.release = chp_release;

Doesn't this leave chp->dev.bus still holding whatever old value it
had laying around before? Unless I'm missing something, it looks to
me like this diff causes a change in the semantics of the code.

Perhaps it would be better to memset() the entire struct (chp->dev, in
this case) to zero, before assigning to individual fields, so there is
no possibility of old remnant data still being left laying around?

The structure is allocated with kzalloc().

--
blue skies,
Martin
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