net/tap: fix multi process reply buffer

A successful call to rte_mp_request_sync does not guarantee that there
are any messages in the buffer, and this should be checked for before
accessing data in the message. Buffer can be empty if IPC is disabled or
if we decide to ignore replies.

Fixes: c9aa56edec8e ("net/tap: access primary process queues from secondary")
Cc: stable@dpdk.org
Signed-off-by: Herakliusz Lipiec <herakliusz.lipiec@intel.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>

diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
index e9fda8cf6adcb8a09574c58d4fa40d6270abe9b8..7f74b5dc986f27b3b4d57a6782e552321fe1e234 100644 (file)
--- a/drivers/net/tap/rte_eth_tap.c
+++ b/drivers/net/tap/rte_eth_tap.c
@@ -2101,7 +2101,7 @@ tap_mp_attach_queues(const char *port_name, struct rte_eth_dev *dev)
        request.len_param = sizeof(*request_param);
        /* Send request and receive reply */
        ret = rte_mp_request_sync(&request, &replies, &timeout);
-       if (ret < 0) {
+       if (ret < 0 || replies.nb_received != 1) {
                TAP_LOG(ERR, "Failed to request queues from primary: %d",
                        rte_errno);
                return -1;