[PATCH 5.5 062/170] net/mlx5e: kTLS, Fix TCP seq off-by-1 issue in TX resync flow

[Greg Kroah-Hartman]

From: Tariq Toukan <tariqt@xxxxxxxxxxxx>

[ Upstream commit 56917766def72f5afdf4235adb91b6897ff26d9d ]

We have an off-by-1 issue in the TCP seq comparison.
The last sequence number that belongs to the TCP packet's payload
is not "start_seq + len", but one byte before it.
Fix it so the 'ends_before' is evaluated properly.

This fixes a bug that results in error completions in the
kTLS HW offload flows.

Fixes: ffbd9ca94e2e ("net/mlx5e: kTLS, Fix corner-case checks in TX resync flow")
Signed-off-by: Tariq Toukan <tariqt@xxxxxxxxxxxx>
Reviewed-by: Boris Pismenny <borisp@xxxxxxxxxxxx>
Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c
@@ -218,7 +218,7 @@ tx_sync_info_get(struct mlx5e_ktls_offlo
 	 *    this packet was already acknowledged and its record info
 	 *    was released.
 	 */
-	ends_before = before(tcp_seq + datalen, tls_record_start_seq(record));
+	ends_before = before(tcp_seq + datalen - 1, tls_record_start_seq(record));
 
 	if (unlikely(tls_record_is_start_marker(record))) {
 		ret = ends_before ? MLX5E_KTLS_SYNC_SKIP_NO_DATA : MLX5E_KTLS_SYNC_FAIL;