[PATCH net-next v10 5/5] virtio_net: check return value of skb_to_sgvec always

From: Jason A. Donenfeld
Date: Sat Jun 03 2017 - 22:17:09 EST


Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
Reviewed-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx>
Cc: Jason Wang <jasowang@xxxxxxxxxx>
---
drivers/net/virtio_net.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 3e9246cc49c3..57763d30cabb 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1150,7 +1150,7 @@ 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;

@@ -1177,11 +1177,16 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
if (can_push) {
__skb_push(skb, hdr_len);
num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
+ if (unlikely(num_sg < 0))
+ return num_sg;
/* Pull header back to avoid skew in tx bytes calculations. */
__skb_pull(skb, hdr_len);
} else {
sg_set_buf(sq->sg, hdr, hdr_len);
- num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
+ num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len);
+ if (unlikely(num_sg < 0))
+ return num_sg;
+ num_sg++;
}
return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
}
--
2.13.0