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[PATCH net v2] gve: ignore nonrelevant GSO type bits when processing TSO headers

joshwash@google.com posted 1 patch 1 year, 8 months ago
There is a newer version of this series
drivers/net/ethernet/google/gve/gve_tx_dqo.c | 21 +++++---------------
1 file changed, 5 insertions(+), 16 deletions(-)
[PATCH net v2] gve: ignore nonrelevant GSO type bits when processing TSO headers
Posted by joshwash@google.com 1 year, 8 months ago 
From: Joshua Washington <joshwash@google.com>

TSO currently fails when the skb's gso_type field has more than one bit
set.

TSO packets can be passed from userspace using PF_PACKET, TUNTAP and a
few others, using virtio_net_hdr (e.g., PACKET_VNET_HDR). This includes
virtualization, such as QEMU, a real use-case.

The gso_type and gso_size fields as passed from userspace in
virtio_net_hdr are not trusted blindly by the kernel. It adds gso_type
|= SKB_GSO_DODGY to force the packet to enter the software GSO stack
for verification.

This issue might similarly come up when the CWR bit is set in the TCP
header for congestion control, causing the SKB_GSO_TCP_ECN gso_type bit
to be set.

Fixes: a57e5de476be ("gve: DQO: Add TX path")
Signed-off-by: Joshua Washington <joshwash@google.com>
Reviewed-by: Praveen Kaligineedi <pkaligineedi@google.com>
Reviewed-by: Harshitha Ramamurthy <hramamurthy@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Suggested-by: Eric Dumazet <edumazet@google.com>
Acked-by: Andrei Vagin <avagin@gmail.com>
---
 drivers/net/ethernet/google/gve/gve_tx_dqo.c | 21 +++++---------------
 1 file changed, 5 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/google/gve/gve_tx_dqo.c b/drivers/net/ethernet/google/gve/gve_tx_dqo.c
index fe1b26a4d736..a76b407a981b 100644
--- a/drivers/net/ethernet/google/gve/gve_tx_dqo.c
+++ b/drivers/net/ethernet/google/gve/gve_tx_dqo.c
@@ -551,32 +551,21 @@ static int gve_prep_tso(struct sk_buff *skb)
 	 * - Hypervisor enforces a limit of 9K MTU
 	 * - Kernel will not produce a TSO larger than 64k
 	 */
-
 	if (unlikely(skb_shinfo(skb)->gso_size < GVE_TX_MIN_TSO_MSS_DQO))
 		return -1;
 
+	if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
+		return -EINVAL;
+
 	/* Needed because we will modify header. */
 	err = skb_cow_head(skb, 0);
 	if (err < 0)
 		return err;
 
 	tcp = tcp_hdr(skb);
-
-	/* Remove payload length from checksum. */
 	paylen = skb->len - skb_transport_offset(skb);
-
-	switch (skb_shinfo(skb)->gso_type) {
-	case SKB_GSO_TCPV4:
-	case SKB_GSO_TCPV6:
-		csum_replace_by_diff(&tcp->check,
-				     (__force __wsum)htonl(paylen));
-
-		/* Compute length of segmentation header. */
-		header_len = skb_tcp_all_headers(skb);
-		break;
-	default:
-		return -EINVAL;
-	}
+	csum_replace_by_diff(&tcp->check, (__force __wsum)htonl(paylen));
+	header_len = skb_tcp_all_headers(skb);
 
 	if (unlikely(header_len > GVE_TX_MAX_HDR_SIZE_DQO))
 		return -EINVAL;
-- 
2.45.2.505.gda0bf45e8d-goog
Re: [PATCH net v2] gve: ignore nonrelevant GSO type bits when processing TSO headers
Posted by Willem de Bruijn 1 year, 8 months ago 
joshwash@ wrote:
> From: Joshua Washington <joshwash@google.com>
> 
> TSO currently fails when the skb's gso_type field has more than one bit
> set.
> 
> TSO packets can be passed from userspace using PF_PACKET, TUNTAP and a
> few others, using virtio_net_hdr (e.g., PACKET_VNET_HDR). This includes
> virtualization, such as QEMU, a real use-case.
> 
> The gso_type and gso_size fields as passed from userspace in
> virtio_net_hdr are not trusted blindly by the kernel. It adds gso_type
> |= SKB_GSO_DODGY to force the packet to enter the software GSO stack
> for verification.
> 
> This issue might similarly come up when the CWR bit is set in the TCP
> header for congestion control, causing the SKB_GSO_TCP_ECN gso_type bit
> to be set.
> 
> Fixes: a57e5de476be ("gve: DQO: Add TX path")
> Signed-off-by: Joshua Washington <joshwash@google.com>
> Reviewed-by: Praveen Kaligineedi <pkaligineedi@google.com>
> Reviewed-by: Harshitha Ramamurthy <hramamurthy@google.com>
> Reviewed-by: Willem de Bruijn <willemb@google.com>
> Suggested-by: Eric Dumazet <edumazet@google.com>
> Acked-by: Andrei Vagin <avagin@gmail.com>

I did not mean to ask for a revision. When you send a v2, please do include
a changelog

> ---
>  drivers/net/ethernet/google/gve/gve_tx_dqo.c | 21 +++++---------------
>  1 file changed, 5 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/net/ethernet/google/gve/gve_tx_dqo.c b/drivers/net/ethernet/google/gve/gve_tx_dqo.c
> index fe1b26a4d736..a76b407a981b 100644
> --- a/drivers/net/ethernet/google/gve/gve_tx_dqo.c
> +++ b/drivers/net/ethernet/google/gve/gve_tx_dqo.c
> @@ -551,32 +551,21 @@ static int gve_prep_tso(struct sk_buff *skb)
>  	 * - Hypervisor enforces a limit of 9K MTU
>  	 * - Kernel will not produce a TSO larger than 64k
>  	 */
> -

Accidental removal?

>  	if (unlikely(skb_shinfo(skb)->gso_size < GVE_TX_MIN_TSO_MSS_DQO))
>  		return -1;
>  
> +	if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
> +		return -EINVAL;
> +
Re: [PATCH net v2] gve: ignore nonrelevant GSO type bits when processing TSO headers
Posted by Eric Dumazet 1 year, 8 months ago 
On Fri, Jun 7, 2024 at 8:10 AM <joshwash@google.com> wrote:
>
> From: Joshua Washington <joshwash@google.com>
>
> TSO currently fails when the skb's gso_type field has more than one bit
> set.
>
> TSO packets can be passed from userspace using PF_PACKET, TUNTAP and a
> few others, using virtio_net_hdr (e.g., PACKET_VNET_HDR). This includes
> virtualization, such as QEMU, a real use-case.
>
> The gso_type and gso_size fields as passed from userspace in
> virtio_net_hdr are not trusted blindly by the kernel. It adds gso_type
> |= SKB_GSO_DODGY to force the packet to enter the software GSO stack
> for verification.
>
> This issue might similarly come up when the CWR bit is set in the TCP
> header for congestion control, causing the SKB_GSO_TCP_ECN gso_type bit
> to be set.
>
> Fixes: a57e5de476be ("gve: DQO: Add TX path")
> Signed-off-by: Joshua Washington <joshwash@google.com>
> Reviewed-by: Praveen Kaligineedi <pkaligineedi@google.com>
> Reviewed-by: Harshitha Ramamurthy <hramamurthy@google.com>
> Reviewed-by: Willem de Bruijn <willemb@google.com>
> Suggested-by: Eric Dumazet <edumazet@google.com>
> Acked-by: Andrei Vagin <avagin@gmail.com>

Reviewed-by: Eric Dumazet <edumazet@google.com>
[PATCH net v3] gve: ignore nonrelevant GSO type bits when processing TSO headers
Posted by joshwash@google.com 1 year, 8 months ago 
From: Joshua Washington <joshwash@google.com>

TSO currently fails when the skb's gso_type field has more than one bit
set.

TSO packets can be passed from userspace using PF_PACKET, TUNTAP and a
few others, using virtio_net_hdr (e.g., PACKET_VNET_HDR). This includes
virtualization, such as QEMU, a real use-case.

The gso_type and gso_size fields as passed from userspace in
virtio_net_hdr are not trusted blindly by the kernel. It adds gso_type
|= SKB_GSO_DODGY to force the packet to enter the software GSO stack
for verification.

This issue might similarly come up when the CWR bit is set in the TCP
header for congestion control, causing the SKB_GSO_TCP_ECN gso_type bit
to be set.

Fixes: a57e5de476be ("gve: DQO: Add TX path")
Signed-off-by: Joshua Washington <joshwash@google.com>
Reviewed-by: Praveen Kaligineedi <pkaligineedi@google.com>
Reviewed-by: Harshitha Ramamurthy <hramamurthy@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Suggested-by: Eric Dumazet <edumazet@google.com>
Acked-by: Andrei Vagin <avagin@gmail.com>

v2 - Remove unnecessary comments, remove line break between fixes tag
and signoffs.

v3 - Add back unrelated empty line removal.
---
 drivers/net/ethernet/google/gve/gve_tx_dqo.c | 20 +++++---------------
 1 file changed, 5 insertions(+), 15 deletions(-)

diff --git a/drivers/net/ethernet/google/gve/gve_tx_dqo.c b/drivers/net/ethernet/google/gve/gve_tx_dqo.c
index fe1b26a4d736..0b3cca3fc792 100644
--- a/drivers/net/ethernet/google/gve/gve_tx_dqo.c
+++ b/drivers/net/ethernet/google/gve/gve_tx_dqo.c
@@ -555,28 +555,18 @@ static int gve_prep_tso(struct sk_buff *skb)
 	if (unlikely(skb_shinfo(skb)->gso_size < GVE_TX_MIN_TSO_MSS_DQO))
 		return -1;
 
+	if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
+		return -EINVAL;
+
 	/* Needed because we will modify header. */
 	err = skb_cow_head(skb, 0);
 	if (err < 0)
 		return err;
 
 	tcp = tcp_hdr(skb);
-
-	/* Remove payload length from checksum. */
 	paylen = skb->len - skb_transport_offset(skb);
-
-	switch (skb_shinfo(skb)->gso_type) {
-	case SKB_GSO_TCPV4:
-	case SKB_GSO_TCPV6:
-		csum_replace_by_diff(&tcp->check,
-				     (__force __wsum)htonl(paylen));
-
-		/* Compute length of segmentation header. */
-		header_len = skb_tcp_all_headers(skb);
-		break;
-	default:
-		return -EINVAL;
-	}
+	csum_replace_by_diff(&tcp->check, (__force __wsum)htonl(paylen));
+	header_len = skb_tcp_all_headers(skb);
 
 	if (unlikely(header_len > GVE_TX_MAX_HDR_SIZE_DQO))
 		return -EINVAL;
-- 
2.45.2.505.gda0bf45e8d-goog
Re: [PATCH net v3] gve: ignore nonrelevant GSO type bits when processing TSO headers
Posted by Jakub Kicinski 1 year, 8 months ago 
On Mon, 10 Jun 2024 15:57:18 -0700 joshwash@google.com wrote:
> v2 - Remove unnecessary comments, remove line break between fixes tag
> and signoffs.
> 
> v3 - Add back unrelated empty line removal.

Read the maintainer info again, please:
https://www.kernel.org/doc/html/next/process/maintainer-netdev.html
we prefer no in-reply to postings.
Re: [PATCH net v3] gve: ignore nonrelevant GSO type bits when processing TSO headers
Posted by Joshua Washington 1 year, 8 months ago 
My apologies. I'll send an updated patch tomorrow without --in-reply-to.

On Mon, Jun 10, 2024 at 5:27 PM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Mon, 10 Jun 2024 15:57:18 -0700 joshwash@google.com wrote:
> > v2 - Remove unnecessary comments, remove line break between fixes tag
> > and signoffs.
> >
> > v3 - Add back unrelated empty line removal.
>
> Read the maintainer info again, please:
> https://www.kernel.org/doc/html/next/process/maintainer-netdev.html
> we prefer no in-reply to postings.



-- 

Joshua Washington | Software Engineer | joshwash@google.com | (414) 366-4423
Re: [PATCH net v3] gve: ignore nonrelevant GSO type bits when processing TSO headers
Posted by Jakub Kicinski 1 year, 8 months ago 
On Mon, 10 Jun 2024 19:26:32 -0700 Joshua Washington wrote:
> My apologies. I'll send an updated patch tomorrow without --in-reply-to.

No need, it's still in patchwork, it was just a note for the future.
I should have made that more clear, I realized that after hitting send.

Patchew 2.1-devel-b67e4c2

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