general protection fault vs Oops

[Subhashini Rao Beerisetty]

On Mon, May 18, 2020 at 2:16 AM Cong Wang <xiyou.wangcong at gmail.com> wrote:
>
> On Sat, May 16, 2020 at 9:16 AM Subhashini Rao Beerisetty
> <subhashbeerisetty at gmail.com> wrote:
> > Yes, those are out-of-tree modules. Basically, my question is, in
> > general what is the difference between 'general protection fault' and
> > 'Oops' failure in kernel mode.
>
> For your case, they are likely just different consequences of a same
> memory error. Let's assume it is a use-after-free, the behavior is UAF
> is undefined: If that memory freed by kernel is also unmapped from
> kernel address space, you would get a page fault when using it
> afterward, that is an Oops. Or if that memory freed by kernel gets
> reallocated and remapped as read-only, you would get a general
> protection error when you writing to it afterward.
Cool, thanks for the clarification.