Re: Mainline kernel crashes, was Re: RFC: remove set_fs for m68k

Finn Thain
2021-09-13T05:23:03Z

On Mon, 13 Sep 2021, Michael Schmitz wrote:

> >
> > [23982.680000] list_add corruption. next->prev should be prev
> > (00b51e98), but was 00bb22d8. (next=00b75cd0).
>
> I chased a similar list corruption bug (shadow LRU list corrupt in
> mm/workingset.c:shadow_lru_isolate()) in 4.10. I believe that was
> related to an out of bounds memory access - maybe get_reg() from
> drivers/char/random.c but it might have been something else.
>
> That bug had disappeared in 4.12, haven't seen it ever since.
>

Do all of your builds have BUG_ON_DATA_CORRUPTION and DEBUG_LIST enabled?

>
> Incidentally - have you ever checked whether Al Viro's signal handling
> fixes have an impact on these bugs?
>

I will try that patch series if you think it is related.

So far the problem seems to be confined to one machine. Stress tests on
other mac models did not yet reproduce the problem.