[PATCH 5.7 091/120] net/mlx5e: fix bpf_prog reference count leaks in mlx5e_alloc_rq

From: Greg Kroah-Hartman
Date: Mon Aug 03 2020 - 08:25:13 EST

From: Xin Xiong <xiongx18@xxxxxxxxxxxx>

[ Upstream commit e692139e6af339a1495ef401b2d95f7f9d1c7a44 ]

The function invokes bpf_prog_inc(), which increases the reference
count 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
either mlx5_wq_ll_create() or mlx5_wq_cyc_create() fails, the function
simply returns the error code and forgets to drop the reference count
increased earlier, causing a reference count leak of "rq->xdp_prog".

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

Fixes: 422d4c401edd ("net/mlx5e: RX, Split WQ objects for different RQ types")
Signed-off-by: Xin Xiong <xiongx18@xxxxxxxxxxxx>
Signed-off-by: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx>
Signed-off-by: Xin Tan <tanxin.ctf@xxxxxxxxx>
Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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 b485eec812111..9861c9e42c0a7 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -422,7 +422,7 @@ static int mlx5e_alloc_rq(struct mlx5e_channel *c,
err = mlx5_wq_ll_create(mdev, &rqp->wq, rqc_wq, &rq->mpwqe.wq,
if (err)
- return err;
+ goto err_rq_wq_destroy;

rq->mpwqe.wq.db = &rq->mpwqe.wq.db[MLX5_RCV_DBR];

@@ -475,7 +475,7 @@ static int mlx5e_alloc_rq(struct mlx5e_channel *c,
err = mlx5_wq_cyc_create(mdev, &rqp->wq, rqc_wq, &rq->wqe.wq,
if (err)
- return err;
+ goto err_rq_wq_destroy;

rq->wqe.wq.db = &rq->wqe.wq.db[MLX5_RCV_DBR];