Re: Segfault in hw/scsi/scsi-disk.c caused by null pointer

[Peter Maydell]

On Tue, 9 Aug 2022 at 17:26, Denis Krienbühl <denis@href.ch> wrote:
> On 9 Aug 2022, at 18:15, Peter Maydell <peter.maydell@linaro.org> wrote:
>> My wild guess is that there's a race condition somewhere such
>> that when you're doing this huge amount of detaches, very rarely
>> a disk is detached and deleted but this INQUIRY request is
>> incorrectly still sent to the disk (which being a freed object,
>> might be overwritten with other stuff). But that is purely a guess.
>
> So.. should this be something I create a bug report for?
>
>
>> If you can repro this on current head-of-git, or at least on
>> the most recent release, then yes, file a bug report.

> The best I can currently do is start to log what’s going on. Since
> I’m not at all familiar with SCSI and this code-base, do you have
> any tipps on what I should log to maybe find out where this
> race-condition occurs?
>
> Or if there’s any kind of documentation I could read to understand
> better what is going on in the hw/scsi subsystem and how I should
> navigate the code. After reading your explanation we’ll probably
> look for other workarounds, but I would love to understand what’s
> going on.

Paolo and Fam are the SCSI subsystem maintainers. They might know
whether this sounds like a bug that's already been fixed at some
point, or have other suggestions.

Context (ie link to the start of this thread on the list archive):
https://lists.gnu.org/archive/html/qemu-discuss/2022-08/msg00011.html

thanks
-- PMM