[PATCH] net/netvsc: fix use after free in cache list cleanup

[Stephen Hemminger]

The variable cache is referred to by LIST_FOREACH macro
after was freed. Replace by the standard LIST_FOREACH_SAFE
from BSD (and other drivers).

Fixes: 9a9d038c782e ("net/netvsc: cache device parameters for hotplug events")
Cc: longli at microsoft.com
Cc: stable at dpdk.org

Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
---
 drivers/net/netvsc/hn_ethdev.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/net/netvsc/hn_ethdev.c b/drivers/net/netvsc/hn_ethdev.c
index dc765e88f7..6584819f4f 100644
--- a/drivers/net/netvsc/hn_ethdev.c
+++ b/drivers/net/netvsc/hn_ethdev.c
@@ -41,6 +41,13 @@
 #include "hn_nvs.h"
 #include "ndis.h"
 
+#ifndef LIST_FOREACH_SAFE
+#define LIST_FOREACH_SAFE(var, head, field, tvar)			\
+	for ((var) = LIST_FIRST((head));				\
+	    (var) && ((tvar) = LIST_NEXT((var), field), 1);		\
+	    (var) = (tvar))
+#endif
+
 #define HN_TX_OFFLOAD_CAPS (RTE_ETH_TX_OFFLOAD_IPV4_CKSUM | \
 			    RTE_ETH_TX_OFFLOAD_TCP_CKSUM  | \
 			    RTE_ETH_TX_OFFLOAD_UDP_CKSUM  | \
@@ -1479,14 +1486,14 @@ static int populate_cache_list(void)
 
 static void remove_cache_list(void)
 {
-	struct da_cache *cache;
+	struct da_cache *cache, *tmp;
 
 	rte_spinlock_lock(&netvsc_lock);
 	da_cache_usage--;
 	if (da_cache_usage)
 		goto out;
 
-	LIST_FOREACH(cache, &da_cache_list, list) {
+	LIST_FOREACH_SAFE(cache, &da_cache_list, list, tmp) {
 		LIST_REMOVE(cache, list);
 		free(cache);
 	}
-- 
2.51.0