[PATCH] net/mlx5e: Fix freeing of unassigned pointer

From: Alex Dewar
Date: Sat Oct 03 2020 - 07:11:20 EST


Commit ff7ea04ad579 ("net/mlx5e: Fix potential null pointer dereference")
added some missing null checks but the error handling in
mlx5e_alloc_flow() was left broken: the variable attr is passed to kfree
although it is never assigned to and never needs to be freed in this
function. Fix this.

Addresses-Coverity-ID: 1497536 ("Memory - illegal accesses")
Fixes: ff7ea04ad579 ("net/mlx5e: Fix potential null pointer dereference")
Signed-off-by: Alex Dewar <alex.dewar90@xxxxxxxxx>
---
drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index a0c356987e1a..88298e96c4ea 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -4536,13 +4536,14 @@ 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 err = -ENOMEM;
int out_index;

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

flow->flags = flow_flags;
flow->cookie = f->cookie;
@@ -4550,7 +4551,7 @@ mlx5e_alloc_flow(struct mlx5e_priv *priv, int attr_size,

attr = mlx5_alloc_flow_attr(get_flow_name_space(flow));
if (!attr)
- goto err_free;
+ goto err_free_parse_attr;

flow->attr = attr;

@@ -4566,11 +4567,11 @@ 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