SW VLAN insertion relies on Ethernet addresses location in contigous memory (do not split across mbuf segments). There is no any formal requirements on data location and mbuf structure which guarantee it. So, check it explicitly to avoid corrupted packets if the condition is violated. Typically software VLAN insertion is done on Tx prepare stage and application will get indication that the packet is invalid and cannot be transmitted.
Signed-off-by: Andrew Rybchenko <arybche...@solarflare.com> --- lib/librte_net/rte_ether.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/lib/librte_net/rte_ether.h b/lib/librte_net/rte_ether.h index 0ae4e75b6c..d7c076bba8 100644 --- a/lib/librte_net/rte_ether.h +++ b/lib/librte_net/rte_ether.h @@ -357,6 +357,10 @@ static inline int rte_vlan_insert(struct rte_mbuf **m) if (!RTE_MBUF_DIRECT(*m) || rte_mbuf_refcnt_read(*m) > 1) return -EINVAL; + /* Can't insert header if the first segment is too short */ + if (rte_pktmbuf_data_len(*m) < 2 * RTE_ETHER_ADDR_LEN) + return -EINVAL; + oh = rte_pktmbuf_mtod(*m, struct rte_ether_hdr *); nh = (struct rte_ether_hdr *) rte_pktmbuf_prepend(*m, sizeof(struct rte_vlan_hdr)); -- 2.17.1