Re: [PATCH] aio: fix mremap after fork null-deref

[Andrew Morton]

On Fri,  4 Nov 2022 17:25:19 -0400 Seth Jenkins <sethjenkins@xxxxxxxxxx> wrote:

> Commit e4a0d3e720e7 ("aio: Make it possible to remap aio ring") introduced
> a null-deref if mremap is called on an old aio mapping after fork as
> mm->ioctx_table will be set to NULL.
> 

Is this a theoretical thing, or has this oops actually been observed?