net/mlx5e: SHAMPO, Fix invalid WQ linked list unlink

[ Upstream commit fba8334721e266f92079632598e46e5f89082f30 ]

When all the strides in a WQE have been consumed, the WQE is unlinked
from the WQ linked list (mlx5_wq_ll_pop()). For SHAMPO, it is possible
to receive CQEs with 0 consumed strides for the same WQE even after the
WQE is fully consumed and unlinked. This triggers an additional unlink
for the same wqe which corrupts the linked list.

Fix this scenario by accepting 0 sized consumed strides without
unlinking the WQE again.

Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/r/20240603212219.1037656-4-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index b5333da20e8a7c8c36a86e53ab3b36edd6540098..cdc84a27a04edf1153768877cb6d1af8d8e8ee9a 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -2374,6 +2374,9 @@ mpwrq_cqe_out:
        if (likely(wi->consumed_strides < rq->mpwqe.num_strides))
                return;
 
+       if (unlikely(!cstrides))
+               return;
+
        wq  = &rq->mpwqe.wq;
        wqe = mlx5_wq_ll_get_wqe(wq, wqe_id);
        mlx5_wq_ll_pop(wq, cqe->wqe_id, &wqe->next.next_wqe_index);