Re: [PATCH v2] usb: dwc3: core: Prevent USB core invalid event buffer address access

[Thinh Nguyen]

On Mon, Aug 19, 2024, Krishna Kurapati wrote:
> 
> 
> On 8/8/2024 5:35 PM, Selvarasu Ganesan wrote:
> > This commit addresses an issue where the USB core could access an
> > invalid event buffer address during runtime suspend, potentially causing
> > SMMU faults and other memory issues. The problem arises from the
> > following sequence.
> >          1. In dwc3_gadget_suspend, there is a chance of a timeout when
> >          moving the USB core to the halt state after clearing the
> >          run/stop bit by software.
> >          2. In dwc3_core_exit, the event buffer is cleared regardless of
> >          the USB core's status, which may lead to an SMMU faults and
> >          other memory issues. if the USB core tries to access the event
> >          buffer address.
> > 
> > To prevent this issue, this commit ensures that the event buffer address
> > is not cleared by software  when the USB core is active during runtime
> > suspend by checking its status before clearing the buffer address.
> > 
> > Cc: stable@xxxxxxxxxxxxxxx
> > Fixes: 89d7f9629946 ("usb: dwc3: core: Skip setting event buffers for host only controllers")
> 
> I don't think the fixes tag is right.
> 
> This fix is independent of whether controller is host only capable or not.
> This is fixing the original commit that introduced the cleanup call.
> 

You're reviewing outdated patch. This was brought up to attention
prior[*]. The latest patch is v3, which does not have this Fixes tag.

[*] https://lore.kernel.org/linux-usb/8526e46f-30f2-4f24-8874-624b66aa54b1@xxxxxxxxxxx/T/#m7244209bc610c592ff91ffc72cb5acad2b2ff9ac

Thanks,
Thinh