[PATCH net-next] net: virtio: fix virtnet_sq_free_stats initialization

[PATCH net-next] net: virtio: fix virtnet_sq_free_stats initialization

[Jean-Philippe Brucker]

Commit c8bd1f7f3e61 ("virtio_net: add support for Byte Queue Limits")
added two new fields to struct virtnet_sq_free_stats, but commit
23c81a20b998 ("net: virtio: unify code to init stats") accidentally
removed their initialization. In the worst case this can trigger the BUG
at lib/dynamic_queue_limits.c:99 because dql_completed() receives a
random value as count. Initialize the whole structure.

Fixes: 23c81a20b998 ("net: virtio: unify code to init stats")
Reported-by: Aishwarya TCV <aishwarya.tcv@arm.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
---
Both these patches are still in next so it might be possible to fix it
up directly.
---
 drivers/net/virtio_net.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 10d8674eec5d2..f014802522e0f 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -530,7 +530,7 @@ static void __free_old_xmit(struct send_queue *sq, struct netdev_queue *txq,
 	unsigned int len;
 	void *ptr;
 
-	stats->bytes = stats->packets = 0;
+	memset(stats, 0, sizeof(*stats));
 
 	while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
 		if (!is_xdp_frame(ptr)) {

base-commit: 3fe121b622825ff8cc995a1e6b026181c48188db
-- 
2.45.2

Re: [PATCH net-next] net: virtio: fix virtnet_sq_free_stats initialization

[Michael S. Tsirkin]

On Fri, Jul 12, 2024 at 09:03:30AM +0100, Jean-Philippe Brucker wrote:
> Commit c8bd1f7f3e61 ("virtio_net: add support for Byte Queue Limits")
> added two new fields to struct virtnet_sq_free_stats, but commit
> 23c81a20b998 ("net: virtio: unify code to init stats") accidentally
> removed their initialization. In the worst case this can trigger the BUG
> at lib/dynamic_queue_limits.c:99 because dql_completed() receives a
> random value as count. Initialize the whole structure.
> 
> Fixes: 23c81a20b998 ("net: virtio: unify code to init stats")
> Reported-by: Aishwarya TCV <aishwarya.tcv@arm.com>
> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>


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

> ---
> Both these patches are still in next so it might be possible to fix it
> up directly.

I'd be fine with squashing but I don't think it's done in net-next.

> ---
>  drivers/net/virtio_net.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 10d8674eec5d2..f014802522e0f 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -530,7 +530,7 @@ static void __free_old_xmit(struct send_queue *sq, struct netdev_queue *txq,
>  	unsigned int len;
>  	void *ptr;
>  
> -	stats->bytes = stats->packets = 0;
> +	memset(stats, 0, sizeof(*stats));
>  
>  	while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
>  		if (!is_xdp_frame(ptr)) {
> 
> base-commit: 3fe121b622825ff8cc995a1e6b026181c48188db
> -- 
> 2.45.2

Re: [PATCH net-next] net: virtio: fix virtnet_sq_free_stats initialization

[Simon Horman]

On Fri, Jul 12, 2024 at 06:41:34AM -0400, Michael S. Tsirkin wrote:
> On Fri, Jul 12, 2024 at 09:03:30AM +0100, Jean-Philippe Brucker wrote:
> > Commit c8bd1f7f3e61 ("virtio_net: add support for Byte Queue Limits")
> > added two new fields to struct virtnet_sq_free_stats, but commit
> > 23c81a20b998 ("net: virtio: unify code to init stats") accidentally
> > removed their initialization. In the worst case this can trigger the BUG
> > at lib/dynamic_queue_limits.c:99 because dql_completed() receives a
> > random value as count. Initialize the whole structure.
> > 
> > Fixes: 23c81a20b998 ("net: virtio: unify code to init stats")
> > Reported-by: Aishwarya TCV <aishwarya.tcv@arm.com>
> > Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> 
> 
> Acked-by: Michael S. Tsirkin <mst@redhat.com>
> 
> > ---
> > Both these patches are still in next so it might be possible to fix it
> > up directly.
> 
> I'd be fine with squashing but I don't think it's done in net-next.

True, but this patch doesn't apply to net-next.
And 23c81a20b998 ("net: virtio: unify code to init stats")
isn't present in net-next.

...

Re: [PATCH net-next] net: virtio: fix virtnet_sq_free_stats initialization

[Jean-Philippe Brucker]

On Fri, Jul 12, 2024 at 07:20:21PM +0100, Simon Horman wrote:
> On Fri, Jul 12, 2024 at 06:41:34AM -0400, Michael S. Tsirkin wrote:
> > On Fri, Jul 12, 2024 at 09:03:30AM +0100, Jean-Philippe Brucker wrote:
> > > Commit c8bd1f7f3e61 ("virtio_net: add support for Byte Queue Limits")
> > > added two new fields to struct virtnet_sq_free_stats, but commit
> > > 23c81a20b998 ("net: virtio: unify code to init stats") accidentally
> > > removed their initialization. In the worst case this can trigger the BUG
> > > at lib/dynamic_queue_limits.c:99 because dql_completed() receives a
> > > random value as count. Initialize the whole structure.
> > > 
> > > Fixes: 23c81a20b998 ("net: virtio: unify code to init stats")
> > > Reported-by: Aishwarya TCV <aishwarya.tcv@arm.com>
> > > Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> > 
> > 
> > Acked-by: Michael S. Tsirkin <mst@redhat.com>
> > 
> > > ---
> > > Both these patches are still in next so it might be possible to fix it
> > > up directly.
> > 
> > I'd be fine with squashing but I don't think it's done in net-next.
> 
> True, but this patch doesn't apply to net-next.
> And 23c81a20b998 ("net: virtio: unify code to init stats")
> isn't present in net-next.

Oh right, it's in linux-next but it looks like it came from
git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next

Thanks,
Jean