[PATCH AUTOSEL 5.12 051/160] virtio-net: Add validation for used length
From: Sasha Levin <sashal@kernel.org>
Date: 2021-07-06 11:38:22
Also in:
lkml, netdev, virtualization
Subsystem:
networking drivers, the rest, virtio net driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, "Michael S. Tsirkin", Jason Wang
From: Xie Yongji <redacted> [ Upstream commit ad993a95c508417acdeb15244109e009e50d8758 ] This adds validation for used length (might come from an untrusted device) to avoid data corruption or loss. Signed-off-by: Xie Yongji <redacted> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210531135852.113-1-xieyongji@bytedance.com (local) Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/net/virtio_net.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 0824e6999e49..447582fa20a5 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c@@ -660,6 +660,12 @@ static struct sk_buff *receive_small(struct net_device *dev, len -= vi->hdr_len; stats->bytes += len; + 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++; + goto err_len; + } rcu_read_lock(); xdp_prog = rcu_dereference(rq->xdp_prog); if (xdp_prog) {
@@ -761,6 +767,7 @@ static struct sk_buff *receive_small(struct net_device *dev, err_xdp: rcu_read_unlock(); stats->xdp_drops++; +err_len: stats->drops++; put_page(page); xdp_xmit:
@@ -814,6 +821,12 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, head_skb = NULL; stats->bytes += len - vi->hdr_len; + 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; + } rcu_read_lock(); xdp_prog = rcu_dereference(rq->xdp_prog); if (xdp_prog) {
@@ -938,13 +951,6 @@ 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); curr_skb = head_skb;
--
2.30.2