Subject: [net 12/14] net/mlx5e: Fix MACsec SA initialization routine

From: Saeed Mahameed <[email-masked]>
Date: Mon, 21 Nov 2022 18:25:57 -0800

From: Emeel Hakim <[email-masked]>

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 <[email-masked]>
Reviewed-by: Raed Salem <[email-masked]>
Signed-off-by: Saeed Mahameed <[email-masked]>
---
 .../ethernet/mellanox/mlx5/core/en_accel/macsec.c  | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c
index 2ef36cb9555a..8f8a735a4501 100644
--- 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 macsec_context *ctx,
 	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;
 
-- 
2.38.1