netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH net] virtio-net: drop NETIF_F_FRAGLIST
@ 2015-08-04  9:55 Jason Wang
  2015-08-04 10:05 ` Michael S. Tsirkin
  2015-08-04 11:11 ` Sergei Shtylyov
  0 siblings, 2 replies; 4+ messages in thread
From: Jason Wang @ 2015-08-04  9:55 UTC (permalink / raw)
  To: virtualization, netdev, linux-kernel; +Cc: mst, Jason Wang

virtio declares support for NETIF_F_FRAGLIST, but assumes
that there are at most MAX_SKB_FRAGS + 2 fragments which isn't
always true with a fraglist.

A longer fraglist in the skb will make the call to skb_to_sgvec overflow
the sg array, leading to memory corruption.

Drop NETIF_F_FRAGLIST so we only get what we can handle.

Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
The patch is needed for stable.
---
 drivers/net/virtio_net.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 7fbca37..2347a73 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1756,9 +1756,9 @@ static int virtnet_probe(struct virtio_device *vdev)
 	/* Do we support "hardware" checksums? */
 	if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
 		/* This opens up the world of extra features. */
-		dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
+		dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG;
 		if (csum)
-			dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
+			dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG;
 
 		if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
 			dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
-- 
2.1.4

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH net] virtio-net: drop NETIF_F_FRAGLIST
  2015-08-04  9:55 [PATCH net] virtio-net: drop NETIF_F_FRAGLIST Jason Wang
@ 2015-08-04 10:05 ` Michael S. Tsirkin
  2015-08-04 11:11 ` Sergei Shtylyov
  1 sibling, 0 replies; 4+ messages in thread
From: Michael S. Tsirkin @ 2015-08-04 10:05 UTC (permalink / raw)
  To: Jason Wang; +Cc: netdev, linux-kernel, virtualization

On Tue, Aug 04, 2015 at 05:55:45PM +0800, Jason Wang wrote:
> virtio declares support for NETIF_F_FRAGLIST, but assumes
> that there are at most MAX_SKB_FRAGS + 2 fragments which isn't
> always true with a fraglist.
> 
> A longer fraglist in the skb will make the call to skb_to_sgvec overflow
> the sg array, leading to memory corruption.
> 
> Drop NETIF_F_FRAGLIST so we only get what we can handle.
> 
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>

Acked-by: Michael S. Tsirkin <mst@redhat.com>

Especially important now that virtio_net: add gro capability
was merged for net-next, making bridged setups create fraglists.

> ---
> The patch is needed for stable.
> ---
>  drivers/net/virtio_net.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 7fbca37..2347a73 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -1756,9 +1756,9 @@ static int virtnet_probe(struct virtio_device *vdev)
>  	/* Do we support "hardware" checksums? */
>  	if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
>  		/* This opens up the world of extra features. */
> -		dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
> +		dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG;
>  		if (csum)
> -			dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
> +			dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG;
>  
>  		if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
>  			dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
> -- 
> 2.1.4

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH net] virtio-net: drop NETIF_F_FRAGLIST
  2015-08-04  9:55 [PATCH net] virtio-net: drop NETIF_F_FRAGLIST Jason Wang
  2015-08-04 10:05 ` Michael S. Tsirkin
@ 2015-08-04 11:11 ` Sergei Shtylyov
  2015-08-05  2:32   ` Jason Wang
  1 sibling, 1 reply; 4+ messages in thread
From: Sergei Shtylyov @ 2015-08-04 11:11 UTC (permalink / raw)
  To: Jason Wang, virtualization, netdev, linux-kernel; +Cc: mst

Hello.

On 8/4/2015 12:55 PM, Jason Wang wrote:

> virtio declares support for NETIF_F_FRAGLIST, but assumes
> that there are at most MAX_SKB_FRAGS + 2 fragments which isn't
> always true with a fraglist.

> A longer fraglist in the skb will make the call to skb_to_sgvec overflow
> the sg array, leading to memory corruption.

> Drop NETIF_F_FRAGLIST so we only get what we can handle.

> Cc: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
> The patch is needed for stable.
> ---
>   drivers/net/virtio_net.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)

> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 7fbca37..2347a73 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -1756,9 +1756,9 @@ static int virtnet_probe(struct virtio_device *vdev)
>   	/* Do we support "hardware" checksums? */
>   	if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
>   		/* This opens up the world of extra features. */
> -		dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
> +		dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG;
>   		if (csum)
> -			dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
> +			dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG;

    I'd have added spaces around | to match the style seen below.

>   		if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
>   			dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO

MBR, Sergei

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH net] virtio-net: drop NETIF_F_FRAGLIST
  2015-08-04 11:11 ` Sergei Shtylyov
@ 2015-08-05  2:32   ` Jason Wang
  0 siblings, 0 replies; 4+ messages in thread
From: Jason Wang @ 2015-08-05  2:32 UTC (permalink / raw)
  To: Sergei Shtylyov, virtualization, netdev, linux-kernel; +Cc: mst



On 08/04/2015 07:11 PM, Sergei Shtylyov wrote:
> Hello.
>
> On 8/4/2015 12:55 PM, Jason Wang wrote:
>
>> virtio declares support for NETIF_F_FRAGLIST, but assumes
>> that there are at most MAX_SKB_FRAGS + 2 fragments which isn't
>> always true with a fraglist.
>
>> A longer fraglist in the skb will make the call to skb_to_sgvec overflow
>> the sg array, leading to memory corruption.
>
>> Drop NETIF_F_FRAGLIST so we only get what we can handle.
>
>> Cc: Michael S. Tsirkin <mst@redhat.com>
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>> ---
>> The patch is needed for stable.
>> ---
>>   drivers/net/virtio_net.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>
>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>> index 7fbca37..2347a73 100644
>> --- a/drivers/net/virtio_net.c
>> +++ b/drivers/net/virtio_net.c
>> @@ -1756,9 +1756,9 @@ static int virtnet_probe(struct virtio_device
>> *vdev)
>>       /* Do we support "hardware" checksums? */
>>       if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
>>           /* This opens up the world of extra features. */
>> -        dev->hw_features |=
>> NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
>> +        dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG;
>>           if (csum)
>> -            dev->features |=
>> NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
>> +            dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG;
>
>    I'd have added spaces around | to match the style seen below.
>

Ok, will fix this in V2.

>>           if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
>>               dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
>
> MBR, Sergei
>

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2015-08-05  2:32 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2015-08-04  9:55 [PATCH net] virtio-net: drop NETIF_F_FRAGLIST Jason Wang
2015-08-04 10:05 ` Michael S. Tsirkin
2015-08-04 11:11 ` Sergei Shtylyov
2015-08-05  2:32   ` Jason Wang

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).