Re: [PATCH v2 1/9] ata: libata: Fix ata_exec_internal()

[Niklas Cassel <cassel@kernel.org>]

On Tue, May 26, 2026 at 08:56:49AM -0700, Bart Van Assche wrote:
> On 5/26/26 6:43 AM, Niklas Cassel wrote:
> > On Thu, May 21, 2026 at 10:33:29AM -0700, Bart Van Assche wrote:
> > > diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> > > index e76d15411e2a..3d25dec6ac6c 100644
> > > --- a/drivers/ata/libata-core.c
> > > +++ b/drivers/ata/libata-core.c
> > > @@ -1540,6 +1540,7 @@ unsigned int ata_exec_internal(struct ata_device *dev, struct ata_taskfile *tf,
> > >   {
> > >   	struct ata_link *link = dev->link;
> > >   	struct ata_port *ap = link->ap;
> > > +	const bool owns_eh_mutex = ap->host->eh_owner == current;
> > 
> > We have similar code in ata_msleep(), which does:
> > 
> > bool owns_eh = ap && ap->host->eh_owner == current;
> > 
> > do we perhaps want the "ap && " here as well?
> 
> I don't think we need this since ata_exec_internal() unconditionally
> dereferences the "ap" pointer and hence would already trigger a kernel
> crash if "ap" would be NULL. I'm referring to the following statement
> near the start of ata_exec_internal():
> 
> 	spin_lock_irqsave(ap->lock, flags);

I see, thank you!

Normally I would queue this up for the current release, but
considering that this has a Fixes-tag that references a commit
from 2010, and considering that Linus has explicitly said that
fixes that are not serious enough should go into linux-next:

https://lore.kernel.org/lkml/CAHk-=wjt1NiKOdyAMz_DT7NmZ++SizPOhRSi492ukdTnpDzHQw@mail.gmail.com/T/#u

I will queue this fix patch up in for-next.


Kind regards,
Niklas

> 
> > Otherwise, this looks good to me:
> > Reviewed-by: Niklas Cassel <cassel@kernel.org>
> 
> Thanks!
> 
> Bart.