Messages in this thread Patch in this message | | | From | Xie Yongji <> | Subject | [PATCH] virtio-net: Add validation for used length | Date | Tue, 25 May 2021 12:58:38 +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 | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index c4711e23af88..2dcdc1a3c7e8 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -668,6 +668,13 @@ static struct sk_buff *receive_small(struct net_device *dev, void *orig_data; u32 act; + if (unlikely(len > GOOD_PACKET_LEN)) { + pr_debug("%s: rx error: len %u exceeds max size %lu\n", + dev->name, len, GOOD_PACKET_LEN); + dev->stats.rx_length_errors++; + goto err_xdp; + } + if (unlikely(hdr->hdr.gso_type)) goto err_xdp; @@ -739,6 +746,14 @@ static struct sk_buff *receive_small(struct net_device *dev, } rcu_read_unlock(); + if (unlikely(len > GOOD_PACKET_LEN)) { + pr_debug("%s: rx error: len %u exceeds max size %lu\n", + dev->name, len, GOOD_PACKET_LEN); + dev->stats.rx_length_errors++; + put_page(page); + return NULL; + } + skb = build_skb(buf, buflen); if (!skb) { put_page(page); @@ -822,6 +837,13 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, void *data; u32 act; + 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_xdp; + } + /* Transient failure which in theory could occur if * in-flight packets from before XDP was enabled reach * the receive path after XDP is loaded. -- 2.11.0
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