virtio-net: Add validation for used length
[ 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 <xieyongji@bytedance.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210531135852.113-1-xieyongji@bytedance.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:

committed by
Greg Kroah-Hartman

parent
5e039a80a7
commit
c92298d228
@@ -660,6 +660,12 @@ static struct sk_buff *receive_small(struct net_device *dev,
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len -= vi->hdr_len;
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len -= vi->hdr_len;
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stats->bytes += len;
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stats->bytes += len;
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if (unlikely(len > GOOD_PACKET_LEN)) {
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pr_debug("%s: rx error: len %u exceeds max size %d\n",
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dev->name, len, GOOD_PACKET_LEN);
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dev->stats.rx_length_errors++;
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goto err_len;
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}
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rcu_read_lock();
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rcu_read_lock();
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xdp_prog = rcu_dereference(rq->xdp_prog);
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xdp_prog = rcu_dereference(rq->xdp_prog);
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if (xdp_prog) {
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if (xdp_prog) {
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@@ -763,6 +769,7 @@ err:
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err_xdp:
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err_xdp:
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rcu_read_unlock();
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rcu_read_unlock();
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stats->xdp_drops++;
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stats->xdp_drops++;
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err_len:
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stats->drops++;
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stats->drops++;
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put_page(page);
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put_page(page);
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xdp_xmit:
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xdp_xmit:
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@@ -816,6 +823,12 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
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head_skb = NULL;
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head_skb = NULL;
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stats->bytes += len - vi->hdr_len;
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stats->bytes += len - vi->hdr_len;
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if (unlikely(len > truesize)) {
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pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
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dev->name, len, (unsigned long)ctx);
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dev->stats.rx_length_errors++;
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goto err_skb;
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}
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rcu_read_lock();
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rcu_read_lock();
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xdp_prog = rcu_dereference(rq->xdp_prog);
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xdp_prog = rcu_dereference(rq->xdp_prog);
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if (xdp_prog) {
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if (xdp_prog) {
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@@ -943,13 +956,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
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}
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}
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rcu_read_unlock();
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rcu_read_unlock();
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if (unlikely(len > truesize)) {
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pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
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dev->name, len, (unsigned long)ctx);
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dev->stats.rx_length_errors++;
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goto err_skb;
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}
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head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog,
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head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog,
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metasize);
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metasize);
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curr_skb = head_skb;
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curr_skb = head_skb;
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