Messages in this thread Patch in this message | | | From | Xie Yongji <> | Subject | [PATCH v3] virtio-net: Add validation for used length | Date | Fri, 28 May 2021 20:11:57 +0800 |
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This adds validation for used length (might come from an untrusted device) to avoid data corruption or loss.
Signed-off-by: Xie Yongji <xieyongji@bytedance.com> --- drivers/net/virtio_net.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 073fec4c0df1..01f15b65824c 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -732,6 +732,17 @@ static struct sk_buff *receive_small(struct net_device *dev, rcu_read_lock(); xdp_prog = rcu_dereference(rq->xdp_prog); + if (unlikely(len > GOOD_PACKET_LEN)) { + pr_debug("%s: rx error: len %u exceeds max size %d\n", + dev->name, len, GOOD_PACKET_LEN); + dev->stats.rx_length_errors++; + if (xdp_prog) + goto err_xdp; + + rcu_read_unlock(); + put_page(page); + return NULL; + } if (xdp_prog) { struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset; struct xdp_frame *xdpf; @@ -888,6 +899,16 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, rcu_read_lock(); xdp_prog = rcu_dereference(rq->xdp_prog); + if (unlikely(len > truesize)) { + pr_debug("%s: rx error: len %u exceeds truesize %lu\n", + dev->name, len, (unsigned long)ctx); + dev->stats.rx_length_errors++; + if (xdp_prog) + goto err_xdp; + + rcu_read_unlock(); + goto err_skb; + } if (xdp_prog) { struct xdp_frame *xdpf; struct page *xdp_page; @@ -1012,13 +1033,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, } rcu_read_unlock(); - if (unlikely(len > truesize)) { - pr_debug("%s: rx error: len %u exceeds truesize %lu\n", - dev->name, len, (unsigned long)ctx); - dev->stats.rx_length_errors++; - goto err_skb; - } - head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog, metasize, !!headroom); curr_skb = head_skb; -- 2.11.0
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