Re: [PATCH v3] usb: dwc3: core: Prevent USB core invalid event buffer address access

[Selvarasu Ganesan <selvarasu.g@samsung.com>]

On 8/16/2024 3:25 PM, Greg KH wrote:
> On Thu, Aug 15, 2024 at 12:18:31PM +0530, 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 in Exynos platforms. 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 hardware quirk on Exynos platforms, 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@vger.kernel.org # v6.1+
> Any hint as to what commit id this fixes?
>
> thanks,
>
> greg k-h


Hi Greg,

This issue is not related to any particular commit. The given fix is 
address a hardware quirk on the Exynos platform. And we require it to be 
backported on stable kernel 6.1 and above all stable kernel.

Thanks,
Selva


>