[PATCH v3 1/2] net/af_xdp: fix use after free in af_xdp_tx_zc()

[Ariel Otilibili]

tx_bytes is computed after both legs are tested. This might
produce a use after memory free.

The computation is now moved into each leg.

Bugzilla ID: 1440
Fixes: d8a210774e1d ("net/af_xdp: support unaligned umem chunks")
Signed-off-by: Ariel Otilibili <ariel.otilibili at 6wind.com>
---
 drivers/net/af_xdp/rte_eth_af_xdp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
index 814398ba4b44..092bcb73aa0a 100644
--- a/drivers/net/af_xdp/rte_eth_af_xdp.c
+++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
@@ -574,6 +574,7 @@ af_xdp_tx_zc(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 					umem->mb_pool->header_size;
 			offset = offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT;
 			desc->addr = addr | offset;
+			tx_bytes += desc->len;
 			count++;
 		} else {
 			struct rte_mbuf *local_mbuf =
@@ -601,11 +602,10 @@ af_xdp_tx_zc(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 			desc->addr = addr | offset;
 			rte_memcpy(pkt, rte_pktmbuf_mtod(mbuf, void *),
 					desc->len);
+			tx_bytes += desc->len;
 			rte_pktmbuf_free(mbuf);
 			count++;
 		}
-
-		tx_bytes += mbuf->pkt_len;
 	}
 
 out:
-- 
2.30.2