[PATCH 1/3] net: ethernet: bcmasp: fix possible OOB write in bcmasp_netfilt_get_all_active()

[Hangyu Hua]

rule_locs is allocated in ethtool_get_rxnfc and the size is determined by
rule_cnt from user space. So rule_cnt needs to be check before using
rule_locs to avoid OOB writing or NULL pointer dereference.

Fixes: c5d511c49587 ("net: bcmasp: Add support for wake on net filters")
Signed-off-by: Hangyu Hua <hbh25y at gmail.com>
---
 drivers/net/ethernet/broadcom/asp2/bcmasp.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/broadcom/asp2/bcmasp.c b/drivers/net/ethernet/broadcom/asp2/bcmasp.c
index d63d321f3e7b..4df2ca871af8 100644
--- a/drivers/net/ethernet/broadcom/asp2/bcmasp.c
+++ b/drivers/net/ethernet/broadcom/asp2/bcmasp.c
@@ -535,6 +535,9 @@ void bcmasp_netfilt_get_all_active(struct bcmasp_intf *intf, u32 *rule_locs,
 	int j = 0, i;
 
 	for (i = 0; i < NUM_NET_FILTERS; i++) {
+		if (j == *rule_cnt)
+			break;
+
 		if (!priv->net_filters[i].claimed ||
 		    priv->net_filters[i].port != intf->port)
 			continue;
-- 
2.34.1