[PATCH 2/3] net/mlx5e: Clean up error handling in mlx5e_alloc_flow()

From: Alex Dewar
Date: Sun Sep 27 2020 - 07:33:22 EST


The variable flow is used after being allocated but before being
null-checked, which will cause a null pointer dereference if the
allocation failed. Fix this and tidy up the error-checking logic in this
function.

Addresses-Coverity: CID 1497154: Null pointer dereferences (REVERSE_INULL)
Signed-off-by: Alex Dewar <alex.dewar90@xxxxxxxxx>
---
.../net/ethernet/mellanox/mlx5/core/en_tc.c | 20 ++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index b3c57b984a2a..ed308407be6f 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -4536,20 +4536,22 @@ mlx5e_alloc_flow(struct mlx5e_priv *priv, int attr_size,
struct mlx5e_tc_flow_parse_attr *parse_attr;
struct mlx5_flow_attr *attr;
struct mlx5e_tc_flow *flow;
- int out_index, err;
+ int out_index;

flow = kzalloc(sizeof(*flow), GFP_KERNEL);
+ if (!flow)
+ return -ENOMEM;
parse_attr = kvzalloc(sizeof(*parse_attr), GFP_KERNEL);
+ if (!parse_attr)
+ goto err_free_flow;

flow->flags = flow_flags;
flow->cookie = f->cookie;
flow->priv = priv;

attr = mlx5_alloc_flow_attr(get_flow_name_space(flow));
- if (!parse_attr || !flow || !attr) {
- err = -ENOMEM;
- goto err_free;
- }
+ if (!attr)
+ goto err_free_parse_attr;
flow->attr = attr;

for (out_index = 0; out_index < MLX5_MAX_FLOW_FWD_VPORTS; out_index++)
@@ -4564,11 +4566,11 @@ mlx5e_alloc_flow(struct mlx5e_priv *priv, int attr_size,

return 0;

-err_free:
- kfree(flow);
+err_free_parse_attr:
kvfree(parse_attr);
- kfree(attr);
- return err;
+err_free_flow:
+ kfree(flow);
+ return -ENOMEM;
}

static void
--
2.28.0