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

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Apr 02, 2025 at 08:12:06AM +0800, Ying Lu wrote:
> On Tue, Apr 1, 2025 at 9:48 PM Greg KH <gregkh@linuxfoundation.org> wrote:
> >
> > On Tue, Apr 01, 2025 at 08:48:01PM +0800, Ying Lu wrote:
> > > On Tue, Apr 1, 2025 at 6:31 PM Greg KH <gregkh@linuxfoundation.org> wrote:
> > > >
> > > > On Tue, Apr 01, 2025 at 06:18:01PM +0800, Ying Lu wrote:
> > > > > From: luying1 <luying1@xiaomi.com>
> > > > >
> > > > > 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@xiaomi.com>
> > > >
> > > > 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
> >
> > Please mark the commit with that information, you seem to have not done
> > so for the v2 version :(
> Thank you for your response. Could you please confirm if I understand correctly:
> Should we include in our commit message which commit id we're fixing?

No, use the correct "Fixes:" tag format as described in the
documentation.

thanks,

greg k-h