On 8/22/2024 3:03 PM, Greg Kroah-Hartman wrote:
> On Tue, Aug 13, 2024 at 04:48:47PM +0530, Faisal Hassan wrote:
>> Null pointer dereference occurs when accessing 'hcd' to detect speed
>> from dwc3_qcom_suspend after the xhci-hcd is unbound.
>> To avoid this issue, ensure to check for NULL in dwc3_qcom_read_usb2_speed.
>>
>> echo xhci-hcd.0.auto > /sys/bus/platform/drivers/xhci-hcd/unbind
>> xhci_plat_remove() -> usb_put_hcd() -> hcd_release() -> kfree(hcd)
>>
>> Unable to handle kernel NULL pointer dereference at virtual address
>> 0000000000000060
>> Call trace:
>> dwc3_qcom_suspend.part.0+0x17c/0x2d0 [dwc3_qcom]
>> dwc3_qcom_runtime_suspend+0x2c/0x40 [dwc3_qcom]
>> pm_generic_runtime_suspend+0x30/0x44
>> __rpm_callback+0x4c/0x190
>> rpm_callback+0x6c/0x80
>> rpm_suspend+0x10c/0x620
>> pm_runtime_work+0xc8/0xe0
>> process_one_work+0x1e4/0x4f4
>> worker_thread+0x64/0x43c
>> kthread+0xec/0x100
>> ret_from_fork+0x10/0x20
>>
>> Fixes: c5f14abeb52b ("usb: dwc3: qcom: fix peripheral and OTG suspend")
>> Cc: stable@xxxxxxxxxxxxxxx
>> Signed-off-by: Faisal Hassan <quic_faisalh@xxxxxxxxxxx>
>> ---
>> drivers/usb/dwc3/dwc3-qcom.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
>> index 88fb6706a18d..0c7846478655 100644
>> --- a/drivers/usb/dwc3/dwc3-qcom.c
>> +++ b/drivers/usb/dwc3/dwc3-qcom.c
>> @@ -319,13 +319,15 @@ static bool dwc3_qcom_is_host(struct dwc3_qcom *qcom)
>> static enum usb_device_speed dwc3_qcom_read_usb2_speed(struct dwc3_qcom *qcom, int port_index)
>> {
>> struct dwc3 *dwc = platform_get_drvdata(qcom->dwc3);
>> - struct usb_device *udev;
>> + struct usb_device __maybe_unused *udev;
>
> This change is not relevant to this overall patch, please remove it and
> submit it separately if still needed.
Understood. I’ll remove the change from this patch and submit it
separately if it’s still required. Thank you for the feedback!
>
> thanks,
>
> greg k-h
Thanks,
Faisal
