Arm + KASAN + syzbot

[Russell King - ARM Linux admin]

On Tue, Jan 19, 2021 at 11:34:33AM +0100, Dmitry Vyukov wrote:
> My first guess would be is that current itself if NULL. Accesses to
> current->kcov* are well tested on other arches, including using KCOV
> in interrupts, etc.

There is a window in dup_task_struct() where the new thread info has
a NULL ->task pointer, but this will never be the current thread,
and so would not affect current.

If we do have a NULL current, that would cause the kernel to explode,
since a context switch to or from such a case would dereference a NULL
pointer.

So, I think your theory is highly unlikely.

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