Re: virtio-net: kernel panic in virtio_net.c

[Xuan Zhuo <xuanzhuo@linux.alibaba.com>]

On Sat, 9 Oct 2021 07:19:39 +0200, Greg KH <gregkh@linuxfoundation.org> wrote:
> On Sat, Oct 09, 2021 at 12:27:08AM +0800, Xuan Zhuo wrote:
> > On Fri, 8 Oct 2021 10:06:57 +0200, Greg KH <gregkh@linuxfoundation.org> wrote:
> > > On Fri, Oct 08, 2021 at 12:17:26AM +0800, Xuan Zhuo wrote:
> > > > On Thu, 7 Oct 2021 17:25:02 +0200, Greg KH <gregkh@linuxfoundation.org> wrote:
> > > > > On Thu, Oct 07, 2021 at 11:06:12PM +0800, Xuan Zhuo wrote:
> > > > > > On Thu, 07 Oct 2021 14:04:22 +0200, Corentin Noël <corentin.noel@collabora.com> wrote:
> > > > > > > I've been experiencing crashes with 5.14-rc1 and above that do not
> > > > > > > occur with 5.13,
> > > > > >
> > > > > > I should have fixed this problem before. I don't know why, I just looked at the
> > > > > > latest net code, and this commit seems to be lost.
> > > > > >
> > > > > >      1a8024239dacf53fcf39c0f07fbf2712af22864f virtio-net: fix for skb_over_panic inside big mode
> > > > > >
> > > > > > Can you test this patch again?
> > > > >
> > > > > That commit showed up in 5.13-rc5, so 5.14-rc1 and 5.13 should have had
> > > > > it in it, right?
> > > > >
> > > >
> > > > Yes, it may be lost due to conflicts during a certain merge.
> > >
> > > Really?  I tried to apply that again to 5.14 and it did not work.  So I
> > > do not understand what to do here, can you try to explain it better?
> >
> > I took a look, and there is actually another missing patch:
> >
> > A. 8fb7da9e990793299c89ed7a4281c235bfdd31f8 virtio_net: get build_skb() buf by data ptr
> > B. 1a8024239dacf53fcf39c0f07fbf2712af22864f virtio-net: fix for skb_over_panic inside big mode
> >
> > A is replaced by another patch:
> >
> > 	commit c32325b8fdf2f979befb9fd5587918c0d5412db3
> > 	Author: Jakub Kicinski <kuba@kernel.org>
> > 	Date:   Mon Aug 2 10:57:29 2021 -0700
> >
> > 	    virtio-net: realign page_to_skb() after merges
> >
> > 	    We ended up merging two versions of the same patch set:
> >
> > 	    commit 8fb7da9e9907 ("virtio_net: get build_skb() buf by data ptr")
> > 	    commit 5c37711d9f27 ("virtio-net: fix for unable to handle page fault for address")
> >
> > 	    into net, and
> >
> > 	    commit 7bf64460e3b2 ("virtio-net: get build_skb() buf by data ptr")
> > 	    commit 6c66c147b9a4 ("virtio-net: fix for unable to handle page fault for address")
> >
> > 	    into net-next. Redo the merge from commit 126285651b7f ("Merge
> > 	    ra.kernel.org:/pub/scm/linux/kernel/git/netdev/net"), so that
> > 	    the most recent code remains.
> >
> > 	    Acked-by: Michael S. Tsirkin <mst@redhat.com>
> > 	    Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> > 	    Acked-by: Jason Wang <jasowang@redhat.com>
> > 	    Signed-off-by: David S. Miller <davem@davemloft.net>
> >
> > So after this patch, patch B can be applied normally.
> >
> > So on the latest net branch, only lost
> >
> >           1a8024239dacf53fcf39c0f07fbf2712af22864f virtio-net: fix for skb_over_panic inside big mode
>
> Again, I do not know what to do here, can you submit the needed fix to
> the networking developers so this gets fixed?

Michael has already submitted the patch.

https://lore.kernel.org/netdev/20211009091604.84141-1-mst@redhat.com/T/#u

Thanks.

>
> thanks,
>
> greg k-h