1 files changed, 25 insertions, 15 deletions

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 8e8a179aaa49..8855a994e12b 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -910,17 +910,6 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 		goto ok;
 	}
 
-	/*
-	 * Verify that we can indeed put this data into a skb.
-	 * This is here to handle cases when the device erroneously
-	 * tries to receive more than is possible. This is usually
-	 * the case of a broken device.
-	 */
-	if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
-		net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
-		dev_kfree_skb(skb);
-		return NULL;
-	}
 	BUG_ON(offset >= PAGE_SIZE);
 	while (len) {
 		unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
@@ -2112,9 +2101,19 @@ static struct sk_buff *receive_big(struct net_device *dev,
 				   struct virtnet_rq_stats *stats)
 {
 	struct page *page = buf;
-	struct sk_buff *skb =
-		page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, 0);
+	struct sk_buff *skb;
 
+	/* Make sure that len does not exceed the size allocated in
+	 * add_recvbuf_big.
+	 */
+	if (unlikely(len > (vi->big_packets_num_skbfrags + 1) * PAGE_SIZE)) {
+		pr_debug("%s: rx error: len %u exceeds allocated size %lu\n",
+			 dev->name, len,
+			 (vi->big_packets_num_skbfrags + 1) * PAGE_SIZE);
+		goto err;
+	}
+
+	skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, 0);
 	u64_stats_add(&stats->bytes, len - vi->hdr_len);
 	if (unlikely(!skb))
 		goto err;
@@ -2539,6 +2538,13 @@ err_buf:
 	return NULL;
 }
 
+static inline u32
+virtio_net_hash_value(const struct virtio_net_hdr_v1_hash *hdr_hash)
+{
+	return __le16_to_cpu(hdr_hash->hash_value_lo) |
+		(__le16_to_cpu(hdr_hash->hash_value_hi) << 16);
+}
+
 static void virtio_skb_set_hash(const struct virtio_net_hdr_v1_hash *hdr_hash,
 				struct sk_buff *skb)
 {
@@ -2565,7 +2571,7 @@ static void virtio_skb_set_hash(const struct virtio_net_hdr_v1_hash *hdr_hash,
 	default:
 		rss_hash_type = PKT_HASH_TYPE_NONE;
 	}
-	skb_set_hash(skb, __le32_to_cpu(hdr_hash->hash_value), rss_hash_type);
+	skb_set_hash(skb, virtio_net_hash_value(hdr_hash), rss_hash_type);
 }
 
 static void virtnet_receive_done(struct virtnet_info *vi, struct receive_queue *rq,
@@ -3311,6 +3317,10 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb, bool orphan)
 
 	pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
 
+	/* Make sure it's safe to cast between formats */
+	BUILD_BUG_ON(__alignof__(*hdr) != __alignof__(hdr->hash_hdr));
+	BUILD_BUG_ON(__alignof__(*hdr) != __alignof__(hdr->hash_hdr.hdr));
+
 	can_push = vi->any_header_sg &&
 		!((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
 		!skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
@@ -6750,7 +6760,7 @@ static int virtnet_xdp_rx_hash(const struct xdp_md *_ctx, u32 *hash,
 		hash_report = VIRTIO_NET_HASH_REPORT_NONE;
 
 	*rss_type = virtnet_xdp_rss_type[hash_report];
-	*hash = __le32_to_cpu(hdr_hash->hash_value);
+	*hash = virtio_net_hash_value(hdr_hash);
 	return 0;
 }