Re: [PATCH v1 1/1] usbnet:fix NPE during rx_complete

From: Ying Lu
Date: Tue Apr 01 2025 - 08:48:25 EST


On Tue, Apr 1, 2025 at 6:31 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Tue, Apr 01, 2025 at 06:18:01PM +0800, Ying Lu wrote:
> > From: luying1 <luying1@xxxxxxxxxx>
> >
> > Missing usbnet_going_away Check in Critical Path.
> > The usb_submit_urb function lacks a usbnet_going_away
> > validation, whereas __usbnet_queue_skb includes this check.
> >
> > This inconsistency creates a race condition where:
> > A URB request may succeed, but the corresponding SKB data
> > fails to be queued.
> >
> > Subsequent processes:
> > (e.g., rx_complete → defer_bh → __skb_unlink(skb, list))
> > attempt to access skb->next, triggering a NULL pointer
> > dereference (Kernel Panic).
> >
> > Signed-off-by: luying1 <luying1@xxxxxxxxxx>
>
> Please use your name, not an email alias.
>
OK, I have updated. please check the Patch v2

> Also, what commit id does this fix? Should it be applied to stable
> kernels?
The commit id is 04e906839a053f092ef53f4fb2d610983412b904
(usbnet: fix cyclical race on disconnect with work queue)
Should it be applied to stable kernels? -- Yes

> thanks,
>
> greg k-h