From: Emeel Hakim <ehakim@nvidia.com>
Date: Sun, 30 Oct 2022 11:43:24 +0200
Subject: net/mlx5e: Fix MACsec SA initialization routine
Patch-mainline: v6.1-rc7
Git-commit: d20a56b0eb006096a023a59efccb27a277b38344
References: jsc#PED-1549

Currently as part of MACsec SA initialization routine
extended packet number (EPN) object attribute is always
being set without checking if EPN is actually enabled,
the above could lead to a NULL dereference.
Fix by adding such a check.

Fixes: 4411a6c0abd3 ("net/mlx5e: Support MACsec offload extended packet number (EPN)")
Signed-off-by: Emeel Hakim <ehakim@nvidia.com>
Reviewed-by: Raed Salem <raeds@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c |   14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c
@@ -368,15 +368,15 @@ static int mlx5e_macsec_init_sa(struct m
 	obj_attrs.aso_pdn = macsec->aso.pdn;
 	obj_attrs.epn_state = sa->epn_state;
 
-	if (is_tx) {
-		obj_attrs.ssci = cpu_to_be32((__force u32)ctx->sa.tx_sa->ssci);
-		key = &ctx->sa.tx_sa->key;
-	} else {
-		obj_attrs.ssci = cpu_to_be32((__force u32)ctx->sa.rx_sa->ssci);
-		key = &ctx->sa.rx_sa->key;
+	key = (is_tx) ? &ctx->sa.tx_sa->key : &ctx->sa.rx_sa->key;
+
+	if (sa->epn_state.epn_enabled) {
+		obj_attrs.ssci = (is_tx) ? cpu_to_be32((__force u32)ctx->sa.tx_sa->ssci) :
+					   cpu_to_be32((__force u32)ctx->sa.rx_sa->ssci);
+
+		memcpy(&obj_attrs.salt, &key->salt, sizeof(key->salt));
 	}
 
-	memcpy(&obj_attrs.salt, &key->salt, sizeof(key->salt));
 	obj_attrs.replay_window = ctx->secy->replay_window;
 	obj_attrs.replay_protect = ctx->secy->replay_protect;