File dpdk-CVE-2022-2132.patch of Package dpdk.25895

--- a/lib/librte_vhost/virtio_net.c.orig	2022-09-12 14:08:03.411829182 +0200
+++ b/lib/librte_vhost/virtio_net.c	2022-09-12 14:16:08.343096315 +0200
@@ -1388,19 +1388,15 @@ copy_desc_to_mbuf(struct virtio_net *dev
 	uint32_t buf_avail, buf_offset;
 	uint64_t buf_addr, buf_iova, buf_len;
 	uint32_t mbuf_avail, mbuf_offset;
+	uint32_t hdr_remain = dev->vhost_hlen;
 	uint32_t cpy_len;
 	struct rte_mbuf *cur = m, *prev = m;
 	struct virtio_net_hdr tmp_hdr;
 	struct virtio_net_hdr *hdr = NULL;
-	/* A counter to avoid desc dead loop chain */
-	uint16_t vec_idx = 0;
+	uint16_t vec_idx;
 	struct batch_copy_elem *batch_copy = vq->batch_copy_elems;
 	int error = 0;
 
-	buf_addr = buf_vec[vec_idx].buf_addr;
-	buf_iova = buf_vec[vec_idx].buf_iova;
-	buf_len = buf_vec[vec_idx].buf_len;
-
 	if (unlikely(buf_len < dev->vhost_hlen && nr_vec <= 1)) {
 		error = -1;
 		goto out;
@@ -1419,32 +1415,18 @@ copy_desc_to_mbuf(struct virtio_net *dev
 		}
 	}
 
-	/*
-	 * A virtio driver normally uses at least 2 desc buffers
-	 * for Tx: the first for storing the header, and others
-	 * for storing the data.
-	 */
-	if (unlikely(buf_len < dev->vhost_hlen)) {
-		buf_offset = dev->vhost_hlen - buf_len;
-		vec_idx++;
-		buf_addr = buf_vec[vec_idx].buf_addr;
-		buf_iova = buf_vec[vec_idx].buf_iova;
-		buf_len = buf_vec[vec_idx].buf_len;
-		buf_avail  = buf_len - buf_offset;
-	} else if (buf_len == dev->vhost_hlen) {
-		if (unlikely(++vec_idx >= nr_vec))
-			goto out;
-		buf_addr = buf_vec[vec_idx].buf_addr;
-		buf_iova = buf_vec[vec_idx].buf_iova;
-		buf_len = buf_vec[vec_idx].buf_len;
-
-		buf_offset = 0;
-		buf_avail = buf_len;
-	} else {
-		buf_offset = dev->vhost_hlen;
-		buf_avail = buf_vec[vec_idx].buf_len - dev->vhost_hlen;
+	for (vec_idx = 0; vec_idx < nr_vec; vec_idx++) {
+		if (buf_vec[vec_idx].buf_len > hdr_remain)
+			break;
+		hdr_remain -= buf_vec[vec_idx].buf_len;
 	}
 
+	buf_addr = buf_vec[vec_idx].buf_addr;
+	buf_iova = buf_vec[vec_idx].buf_iova;
+	buf_len = buf_vec[vec_idx].buf_len;
+	buf_offset = hdr_remain;
+	buf_avail = buf_vec[vec_idx].buf_len - hdr_remain;
+
 	PRINT_PACKET(dev,
 			(uintptr_t)(buf_addr + buf_offset),
 			(uint32_t)buf_avail, 0);