Re: [PATCH 1/2] usbip: Fix seqnum sign extension issue in vhci_tx_urb

From: Shuah Khan
Date: Wed Jan 15 2025 - 16:14:36 EST


On 12/31/24 09:15, Xiong Nandi wrote:
The atomic_inc_return function returns an int, while priv->seqnum is an
unsigned long. So we must cast the result to u32 to prevent potential
sign extension and size mismatch issues.

Signed-off-by: Xiong Nandi <xndchn@xxxxxxxxx>
---
drivers/usb/usbip/vhci_hcd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c
index b03e5021c25b..f3f260e01791 100644
--- a/drivers/usb/usbip/vhci_hcd.c
+++ b/drivers/usb/usbip/vhci_hcd.c
@@ -675,7 +675,7 @@ static void vhci_tx_urb(struct urb *urb, struct vhci_device *vdev)
spin_lock_irqsave(&vdev->priv_lock, flags);
- priv->seqnum = atomic_inc_return(&vhci_hcd->seqnum);
+ priv->seqnum = (u32)atomic_inc_return(&vhci_hcd->seqnum);
if (priv->seqnum == 0xffff)
dev_info(&urb->dev->dev, "seqnum max\n");

Acked-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>

thanks,
-- Shuah