When parsing the virtio net header and packet header for dequeue offload,
we need to perform sanity check on the packet header to ensure:
- No out-of-boundary memory access.
- The packet header and virtio_net header are valid and aligned.
Fixes: d0cf91303d73 ("vhost: add Tx offload capabilities")
Cc: sta...@dpdk.org
Signed-off-by: Xiao Wang <xiao.w.w...@intel.com>
---
v2:
Allow empty L4 payload for cksum offload.
---
lib/librte_vhost/virtio_net.c | 49 +++++++++++++++++++++++++++++++++++++------
1 file changed, 43 insertions(+), 6 deletions(-)
diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index 583bf379c6..53a8ff2898 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -1821,44 +1821,64 @@ virtio_net_with_host_offload(struct virtio_net *dev)
return false;
}
-static void
-parse_ethernet(struct rte_mbuf *m, uint16_t *l4_proto, void **l4_hdr)
+static int
+parse_ethernet(struct rte_mbuf *m, uint16_t *l4_proto, void **l4_hdr,
+ uint16_t *len)
{
struct rte_ipv4_hdr *ipv4_hdr;
struct rte_ipv6_hdr *ipv6_hdr;
void *l3_hdr = NULL;
struct rte_ether_hdr *eth_hdr;
uint16_t ethertype;
+ uint16_t data_len = m->data_len;
eth_hdr = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
+ if (data_len <= sizeof(struct rte_ether_hdr))
+ return -EINVAL;
+
m->l2_len = sizeof(struct rte_ether_hdr);
ethertype = rte_be_to_cpu_16(eth_hdr->ether_type);
+ data_len -= sizeof(struct rte_ether_hdr);
if (ethertype == RTE_ETHER_TYPE_VLAN) {
+ if (data_len <= sizeof(struct rte_vlan_hdr))
+ return -EINVAL;
+
struct rte_vlan_hdr *vlan_hdr =
(struct rte_vlan_hdr *)(eth_hdr + 1);
m->l2_len += sizeof(struct rte_vlan_hdr);
ethertype = rte_be_to_cpu_16(vlan_hdr->eth_proto);
+ data_len -= sizeof(struct rte_vlan_hdr);
}
l3_hdr = (char *)eth_hdr + m->l2_len;
switch (ethertype) {
case RTE_ETHER_TYPE_IPV4:
+ if (data_len <= sizeof(struct rte_ipv4_hdr))
+ return -EINVAL;
ipv4_hdr = l3_hdr;
*l4_proto = ipv4_hdr->next_proto_id;
m->l3_len = rte_ipv4_hdr_len(ipv4_hdr);
+ if (data_len <= m->l3_len) {
+ m->l3_len = 0;
+ return -EINVAL;
+ }
*l4_hdr = (char *)l3_hdr + m->l3_len;
m->ol_flags |= PKT_TX_IPV4;
+ data_len -= m->l3_len;
break;
case RTE_ETHER_TYPE_IPV6:
+ if (data_len <= sizeof(struct rte_ipv6_hdr))
+ return -EINVAL;
ipv6_hdr = l3_hdr;
*l4_proto = ipv6_hdr->proto;
m->l3_len = sizeof(struct rte_ipv6_hdr);
*l4_hdr = (char *)l3_hdr + m->l3_len;
m->ol_flags |= PKT_TX_IPV6;
+ data_len -= m->l3_len;
break;
default:
m->l3_len = 0;
@@ -1866,6 +1886,9 @@ parse_ethernet(struct rte_mbuf *m, uint16_t *l4_proto,
void **l4_hdr)
*l4_hdr = NULL;
break;
}
+
+ *len = data_len;
+ return 0;
}
static __rte_always_inline void
@@ -1874,24 +1897,30 @@ vhost_dequeue_offload(struct virtio_net_hdr *hdr,
struct rte_mbuf *m)
uint16_t l4_proto = 0;
void *l4_hdr = NULL;
struct rte_tcp_hdr *tcp_hdr = NULL;
+ uint16_t len = 0;
if (hdr->flags == 0 && hdr->gso_type == VIRTIO_NET_HDR_GSO_NONE)
return;
- parse_ethernet(m, &l4_proto, &l4_hdr);
+ if (parse_ethernet(m, &l4_proto, &l4_hdr, &len) < 0)
+ return;
+
if (hdr->flags == VIRTIO_NET_HDR_F_NEEDS_CSUM) {
if (hdr->csum_start == (m->l2_len + m->l3_len)) {
switch (hdr->csum_offset) {
case (offsetof(struct rte_tcp_hdr, cksum)):
- if (l4_proto == IPPROTO_TCP)
+ if (l4_proto == IPPROTO_TCP &&
+ len >= sizeof(struct rte_tcp_hdr))
m->ol_flags |= PKT_TX_TCP_CKSUM;
break;
case (offsetof(struct rte_udp_hdr, dgram_cksum)):
- if (l4_proto == IPPROTO_UDP)
+ if (l4_proto == IPPROTO_UDP &&
+ len >= sizeof(struct rte_udp_hdr))
m->ol_flags |= PKT_TX_UDP_CKSUM;
break;
case (offsetof(struct rte_sctp_hdr, cksum)):
- if (l4_proto == IPPROTO_SCTP)
+ if (l4_proto == IPPROTO_SCTP &&
+ len >= sizeof(struct rte_sctp_hdr))
m->ol_flags |= PKT_TX_SCTP_CKSUM;
break;
default:
@@ -1904,12 +1933,20 @@ vhost_dequeue_offload(struct virtio_net_hdr *hdr,
struct rte_mbuf *m)
switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
case VIRTIO_NET_HDR_GSO_TCPV4:
case VIRTIO_NET_HDR_GSO_TCPV6:
+ if (l4_proto != IPPROTO_TCP ||
+ len <= sizeof(struct rte_tcp_hdr))
+ break;
tcp_hdr = l4_hdr;
+ if (len <= (tcp_hdr->data_off & 0xf0) >> 2)
+ break;
m->ol_flags |= PKT_TX_TCP_SEG;
m->tso_segsz = hdr->gso_size;
m->l4_len = (tcp_hdr->data_off & 0xf0) >> 2;
break;
case VIRTIO_NET_HDR_GSO_UDP:
+ if (l4_proto != IPPROTO_UDP ||
+ len <= sizeof(struct rte_udp_hdr))
+ break;
m->ol_flags |= PKT_TX_UDP_SEG;
m->tso_segsz = hdr->gso_size;
m->l4_len = sizeof(struct rte_udp_hdr);
--
2.15.1
