From: "Michael S. Tsirkin" <mst@redhat.com>
To: anton.ivanov@cambridgegreys.com
Cc: netdev@vger.kernel.org, jasowang@redhat.com,
linux-um@lists.infradead.org, eric.dumazet@gmail.com,
virtualization@lists.linux-foundation.org
Subject: Re: [PATCH v2] virtio: Work around frames incorrectly marked as gso
Date: Mon, 24 Feb 2020 07:46:27 -0500 [thread overview]
Message-ID: <20200224074516-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20200224101912.14074-1-anton.ivanov@cambridgegreys.com>
On Mon, Feb 24, 2020 at 10:19:12AM +0000, anton.ivanov@cambridgegreys.com wrote:
> From: Anton Ivanov <anton.ivanov@cambridgegreys.com>
>
> Some of the locally generated frames marked as GSO which
> arrive at virtio_net_hdr_from_skb() have no GSO_TYPE, no
> fragments (data_len = 0) and length significantly shorter
> than the MTU (752 in my experiments).
>
> This is observed on raw sockets reading off vEth interfaces
> in all 4.x and 5.x kernels I tested.
A bit more info on how to reproduce couldn't hurt here.
>
> These frames are reported as invalid while they are in fact
> gso-less frames.
>
> This patch marks the vnet header as no-GSO for them instead
> of reporting it as invalid.
>
> Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Eric - as you looked at this in the past, would you mind acking please?
> ---
> include/linux/virtio_net.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
> index 0d1fe9297ac6..94fb78c3a2ab 100644
> --- a/include/linux/virtio_net.h
> +++ b/include/linux/virtio_net.h
> @@ -100,8 +100,8 @@ static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb,
> {
> memset(hdr, 0, sizeof(*hdr)); /* no info leak */
>
> - if (skb_is_gso(skb)) {
> - struct skb_shared_info *sinfo = skb_shinfo(skb);
> + struct skb_shared_info *sinfo = skb_shinfo(skb);
> + if (skb_is_gso(skb) && sinfo->gso_type) {
>
> /* This is a hint as to how much should be linear. */
> hdr->hdr_len = __cpu_to_virtio16(little_endian,
> --
> 2.20.1
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WARNING: multiple messages have this Message-ID (diff)
From: "Michael S. Tsirkin" <mst@redhat.com>
To: anton.ivanov@cambridgegreys.com
Cc: netdev@vger.kernel.org,
virtualization@lists.linux-foundation.org,
linux-um@lists.infradead.org, jasowang@redhat.com,
eric.dumazet@gmail.com
Subject: Re: [PATCH v2] virtio: Work around frames incorrectly marked as gso
Date: Mon, 24 Feb 2020 07:46:27 -0500 [thread overview]
Message-ID: <20200224074516-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20200224101912.14074-1-anton.ivanov@cambridgegreys.com>
On Mon, Feb 24, 2020 at 10:19:12AM +0000, anton.ivanov@cambridgegreys.com wrote:
> From: Anton Ivanov <anton.ivanov@cambridgegreys.com>
>
> Some of the locally generated frames marked as GSO which
> arrive at virtio_net_hdr_from_skb() have no GSO_TYPE, no
> fragments (data_len = 0) and length significantly shorter
> than the MTU (752 in my experiments).
>
> This is observed on raw sockets reading off vEth interfaces
> in all 4.x and 5.x kernels I tested.
A bit more info on how to reproduce couldn't hurt here.
>
> These frames are reported as invalid while they are in fact
> gso-less frames.
>
> This patch marks the vnet header as no-GSO for them instead
> of reporting it as invalid.
>
> Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Eric - as you looked at this in the past, would you mind acking please?
> ---
> include/linux/virtio_net.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
> index 0d1fe9297ac6..94fb78c3a2ab 100644
> --- a/include/linux/virtio_net.h
> +++ b/include/linux/virtio_net.h
> @@ -100,8 +100,8 @@ static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb,
> {
> memset(hdr, 0, sizeof(*hdr)); /* no info leak */
>
> - if (skb_is_gso(skb)) {
> - struct skb_shared_info *sinfo = skb_shinfo(skb);
> + struct skb_shared_info *sinfo = skb_shinfo(skb);
> + if (skb_is_gso(skb) && sinfo->gso_type) {
>
> /* This is a hint as to how much should be linear. */
> hdr->hdr_len = __cpu_to_virtio16(little_endian,
> --
> 2.20.1
next prev parent reply other threads:[~2020-02-24 12:46 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-24 10:19 [PATCH v2] virtio: Work around frames incorrectly marked as gso anton.ivanov
2020-02-24 10:19 ` anton.ivanov
2020-02-24 12:37 ` kbuild test robot
2020-02-24 12:37 ` kbuild test robot
2020-02-24 12:37 ` kbuild test robot
2020-02-24 12:37 ` kbuild test robot
2020-02-24 12:46 ` Michael S. Tsirkin [this message]
2020-02-24 12:46 ` Michael S. Tsirkin
2020-02-24 12:51 ` Anton Ivanov
2020-02-24 12:51 ` Anton Ivanov
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