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> --- v4: - Rebase on head of main branch. - Allow empty L4 payload in GSO. v3: - Check data_len before calling rte_pktmbuf_mtod. (David) v2: - Allow empty L4 payload for cksum offload. (Konstantin) --- lib/vhost/virtio_net.c | 52 +++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 45 insertions(+), 7 deletions(-) diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c index 8da8a86a10..351ff0a841 100644 --- a/lib/vhost/virtio_net.c +++ b/lib/vhost/virtio_net.c @@ -2259,44 +2259,64 @@ 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; + + if (data_len <= sizeof(struct rte_ether_hdr)) + return -EINVAL; eth_hdr = rte_pktmbuf_mtod(m, struct rte_ether_hdr *); 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; @@ -2304,6 +2324,9 @@ 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 @@ -2312,21 +2335,27 @@ vhost_dequeue_offload_legacy(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, tcp_len; + + if (parse_ethernet(m, &l4_proto, &l4_hdr, &len) < 0) + return; - parse_ethernet(m, &l4_proto, &l4_hdr); 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: @@ -2339,12 +2368,21 @@ vhost_dequeue_offload_legacy(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; + tcp_len = (tcp_hdr->data_off & 0xf0) >> 2; + if (len < tcp_len) + break; m->ol_flags |= PKT_TX_TCP_SEG; m->tso_segsz = hdr->gso_size; - m->l4_len = (tcp_hdr->data_off & 0xf0) >> 2; + m->l4_len = tcp_len; 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