Re: [PATCH v7 5/5] virtio_net: check return value of skb_to_sgvec always

[Jason A. Donenfeld]

On Tue, May 9, 2017 at 3:50 PM, Jason A. Donenfeld  wrote:
> num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;

(The next submission of this will take into account this + 1 here.
https://git.zx2c4.com/linux-dev/log/?h=jd/safe-skb-vec )

Re: [PATCH v7 5/5] virtio_net: check return value of skb_to_sgvec always

[Jason A. Donenfeld]

On Tue, May 9, 2017 at 3:50 PM, Jason A. Donenfeld  wrote:
> num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;

(The next submission of this will take into account this + 1 here.
https://git.zx2c4.com/linux-dev/log/?h=jd/safe-skb-vec )

[PATCH v7 5/5] virtio_net: check return value of skb_to_sgvec always

[Jason A. Donenfeld]

Signed-off-by: Jason A. Donenfeld 
Cc: "Michael S. Tsirkin" 
Cc: Jason Wang 
---
 drivers/net/virtio_net.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index f36584616e7d..1709fd0b4bf7 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1081,7 +1081,7 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff 
*skb)
struct virtio_net_hdr_mrg_rxbuf *hdr;
const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
struct virtnet_info *vi = sq->vq->vdev->priv;
-   unsigned num_sg;
+   int num_sg;
unsigned hdr_len = vi->hdr_len;
bool can_push;
 
@@ -1114,6 +1114,8 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff 
*skb)
sg_set_buf(sq->sg, hdr, hdr_len);
num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
}
+   if (unlikely(num_sg < 0))
+   return num_sg;
return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
 }
 
-- 
2.12.2

[PATCH v7 5/5] virtio_net: check return value of skb_to_sgvec always

[Jason A. Donenfeld]

Signed-off-by: Jason A. Donenfeld 
Cc: "Michael S. Tsirkin" 
Cc: Jason Wang 
---
 drivers/net/virtio_net.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index f36584616e7d..1709fd0b4bf7 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1081,7 +1081,7 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff 
*skb)
struct virtio_net_hdr_mrg_rxbuf *hdr;
const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
struct virtnet_info *vi = sq->vq->vdev->priv;
-   unsigned num_sg;
+   int num_sg;
unsigned hdr_len = vi->hdr_len;
bool can_push;
 
@@ -1114,6 +1114,8 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff 
*skb)
sg_set_buf(sq->sg, hdr, hdr_len);
num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
}
+   if (unlikely(num_sg < 0))
+   return num_sg;
return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
 }
 
-- 
2.12.2