[dpdk-dev] [PATCH 11/12] vhost/crypto: move to safe GPA translation API

[Maxime Coquelin <maxime.coquelin@redhat.com>]

This patch uses the new rte_vhost_va_from_guest_pa() API
to ensure all the descriptor buffer is mapped contiguously
in the application virtual address space.

It does not handle buffers discontiguous in host virtual
address space, but only return an error.

This issue has been assigned CVE-2018-1059.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/vhost_crypto.c | 65 ++++++++++++++++++++++++++++++++---------
 1 file changed, 51 insertions(+), 14 deletions(-)

diff --git a/lib/librte_vhost/vhost_crypto.c b/lib/librte_vhost/vhost_crypto.c
index c154ef673..c38eb3bb5 100644
--- a/lib/librte_vhost/vhost_crypto.c
+++ b/lib/librte_vhost/vhost_crypto.c
@@ -42,7 +42,7 @@
 		(1 << VIRTIO_CRYPTO_SERVICE_MAC) |			\
 		(1 << VIRTIO_NET_F_CTRL_VQ))
 
-#define GPA_TO_VVA(t, m, a)	((t)(uintptr_t)rte_vhost_gpa_to_vva(m, a))
+#define GPA_TO_VVA(t, m, a, l)	((t)(uintptr_t)rte_vhost_va_from_guest_pa(m, a, l))
 
 static int
 cipher_algo_transform(uint32_t virtio_cipher_algo)
@@ -476,10 +476,18 @@ static struct virtio_crypto_inhdr *
 reach_inhdr(struct vring_desc *head, struct rte_vhost_memory *mem,
 		struct vring_desc *desc)
 {
+	uint64_t dlen;
+	struct virtio_crypto_inhdr *inhdr;
+
 	while (desc->flags & VRING_DESC_F_NEXT)
 		desc = &head[desc->next];
 
-	return GPA_TO_VVA(struct virtio_crypto_inhdr *, mem, desc->addr);
+	dlen = desc->len;
+	inhdr = GPA_TO_VVA(struct virtio_crypto_inhdr *, mem, desc->addr, &dlen);
+	if (unlikely(dlen != desc->len))
+		return NULL;
+
+	return inhdr;
 }
 
 static __rte_always_inline int
@@ -516,10 +524,17 @@ copy_data(void *dst_data, struct vring_desc *head, struct rte_vhost_memory *mem,
 	uint8_t *data = dst_data;
 	uint8_t *src;
 	int left = size;
+	uint64_t dlen;
 
 	rte_prefetch0(&head[desc->next]);
 	to_copy = RTE_MIN(desc->len, (uint32_t)left);
-	src = GPA_TO_VVA(uint8_t *, mem, desc->addr);
+	dlen = desc->len;
+	src = GPA_TO_VVA(uint8_t *, mem, desc->addr, &dlen);
+	if (unlikely(!src || dlen != desc->len)) {
+		VC_LOG_ERR("Failed to map descriptor");
+		return -1;
+	}
+
 	rte_memcpy((uint8_t *)data, src, to_copy);
 	left -= to_copy;
 
@@ -527,7 +542,13 @@ copy_data(void *dst_data, struct vring_desc *head, struct rte_vhost_memory *mem,
 		desc = &head[desc->next];
 		rte_prefetch0(&head[desc->next]);
 		to_copy = RTE_MIN(desc->len, (uint32_t)left);
-		src = GPA_TO_VVA(uint8_t *, mem, desc->addr);
+		dlen = desc->len;
+		src = GPA_TO_VVA(uint8_t *, mem, desc->addr, &dlen);
+		if (unlikely(!src || dlen != desc->len)) {
+			VC_LOG_ERR("Failed to map descriptor");
+			return -1;
+		}
+
 		rte_memcpy(data + size - left, src, to_copy);
 		left -= to_copy;
 	}
@@ -547,10 +568,11 @@ get_data_ptr(struct vring_desc *head, struct rte_vhost_memory *mem,
 		struct vring_desc **cur_desc, uint32_t size)
 {
 	void *data;
+	uint64_t dlen = (*cur_desc)->len;
 
-	data = GPA_TO_VVA(void *, mem, (*cur_desc)->addr);
-	if (unlikely(!data)) {
-		VC_LOG_ERR("Failed to get object");
+	data = GPA_TO_VVA(void *, mem, (*cur_desc)->addr, &dlen);
+	if (unlikely(!data || dlen != (*cur_desc)->len)) {
+		VC_LOG_ERR("Failed to map object");
 		return NULL;
 	}
 
@@ -570,10 +592,17 @@ write_back_data(struct rte_crypto_op *op, struct vhost_crypto_data_req *vc_req)
 	int left = vc_req->wb_len;
 	uint32_t to_write;
 	uint8_t *src_data = mbuf->buf_addr, *dst;
+	uint64_t dlen;
 
 	rte_prefetch0(&head[desc->next]);
 	to_write = RTE_MIN(desc->len, (uint32_t)left);
-	dst = GPA_TO_VVA(uint8_t *, mem, desc->addr);
+	dlen = desc->len;
+	dst = GPA_TO_VVA(uint8_t *, mem, desc->addr, &dlen);
+	if (unlikely(!dst || dlen != desc->len)) {
+		VC_LOG_ERR("Failed to map descriptor");
+		return -1;
+	}
+
 	rte_memcpy(dst, src_data, to_write);
 	left -= to_write;
 	src_data += to_write;
@@ -582,7 +611,13 @@ write_back_data(struct rte_crypto_op *op, struct vhost_crypto_data_req *vc_req)
 		desc = &head[desc->next];
 		rte_prefetch0(&head[desc->next]);
 		to_write = RTE_MIN(desc->len, (uint32_t)left);
-		dst = GPA_TO_VVA(uint8_t *, mem, desc->addr);
+		dlen = desc->len;
+		dst = GPA_TO_VVA(uint8_t *, mem, desc->addr, &dlen);
+		if (unlikely(!dst || dlen != desc->len)) {
+			VC_LOG_ERR("Failed to map descriptor");
+			return -1;
+		}
+
 		rte_memcpy(dst, src_data, to_write);
 		left -= to_write;
 		src_data += to_write;
@@ -873,19 +908,21 @@ vhost_crypto_process_one_req(struct vhost_crypto *vcrypto,
 	struct virtio_crypto_inhdr *inhdr;
 	struct vring_desc *desc = NULL;
 	uint64_t session_id;
+	uint64_t dlen;
 	int err = 0;
 
 	vc_req->desc_idx = desc_idx;
 
 	if (likely(head->flags & VRING_DESC_F_INDIRECT)) {
-		head = GPA_TO_VVA(struct vring_desc *, mem, head->addr);
-		if (unlikely(!head))
-			return 0;
+		dlen = head->len;
+		desc = GPA_TO_VVA(struct vring_desc *, mem, head->addr, &dlen);
+		if (unlikely(!desc || dlen != head->len))
+			return -1;
 		desc_idx = 0;
+	} else {
+		desc = head;
 	}
 
-	desc = head;
-
 	vc_req->mem = mem;
 	vc_req->head = head;
 	vc_req->vq = vq;
-- 
2.14.3