The user is allowed to call ->rx_pkt_burst() even without free
mbufs in the pool. In this scenario we'll fail allocating a rep mbuf
on the first iteration (where pkt is still NULL). This would cause us
to deref a NULL pkt (reset refcount and free).
Fix this by checking the pkt before freeing it.
Fixes: a1bdb71a32da ("net/mlx5: fix crash in Rx")
Signed-off-by: Sagi Grimberg <sagi at grimberg.me>
Acked-by: Adrien Mazarguil <adrien.mazarguil at 6wind.com>
---
Changes from v2:
- fix check-git-log.sh complaints
- collected acked-by tag
Changes from v1:
- check pkt only once in case we failed to allocate a buffer
drivers/net/mlx5/mlx5_rxtx.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index fce3381ae87a..37573668e43e 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -1572,6 +1572,14 @@ mlx5_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts,
uint16_t pkts_n)
rte_prefetch0(wqe);
rep = rte_mbuf_raw_alloc(rxq->mp);
if (unlikely(rep == NULL)) {
+ ++rxq->stats.rx_nombuf;
+ if (!pkt) {
+ /*
+ * no buffers before we even started,
+ * bail out silently.
+ */
+ break;
+ }
while (pkt != seg) {
assert(pkt != (*rxq->elts)[idx]);
seg = NEXT(pkt);
@@ -1579,7 +1587,6 @@ mlx5_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts,
uint16_t pkts_n)
__rte_mbuf_raw_free(pkt);
pkt = seg;
}
- ++rxq->stats.rx_nombuf;
break;
}
if (!pkt) {
--
1.9.1
