Subject: [PATCH] net/mlx5e: fix bpf_prog refcnt leaks in mlx5e_alloc_rq

From: Xin Xiong <[email-masked]>
Date: Wed, 29 Jul 2020 20:33:34 +0800

The function invokes bpf_prog_inc(), which increases the refcount of a
bpf_prog object "rq->xdp_prog" if the object isn't NULL.

The refcount leak issues take place in two error handling paths. When
mlx5_wq_ll_create() or mlx5_wq_cyc_create() fails, the function simply
returns the error code and forgets to drop the refcount increased
earlier, causing a refcount leak of "rq->xdp_prog".

Fix this issue by jumping to the error handling path err_rq_wq_destroy
when either function fails.

Signed-off-by: Xin Xiong <[email-masked]>
Signed-off-by: Xiyu Yang <[email-masked]>
Signed-off-by: Xin Tan <[email-masked]>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index a836a02a2116..8e1b1ab416d8 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -419,7 +419,7 @@ static int mlx5e_alloc_rq(struct mlx5e_channel *c,
 		err = mlx5_wq_ll_create(mdev, &rqp->wq, rqc_wq, &rq->mpwqe.wq,
 					&rq->wq_ctrl);
 		if (err)
-			return err;
+			goto err_rq_wq_destroy;
 
 		rq->mpwqe.wq.db = &rq->mpwqe.wq.db[MLX5_RCV_DBR];
 
@@ -470,7 +470,7 @@ static int mlx5e_alloc_rq(struct mlx5e_channel *c,
 		err = mlx5_wq_cyc_create(mdev, &rqp->wq, rqc_wq, &rq->wqe.wq,
 					 &rq->wq_ctrl);
 		if (err)
-			return err;
+			goto err_rq_wq_destroy;
 
 		rq->wqe.wq.db = &rq->wqe.wq.db[MLX5_RCV_DBR];
 
-- 
2.25.1