Re: [PATCH net 1/2] net/mlx5e: fix memory leak in mlx5e_fs_tt_redirect_any_create

On 2023/6/30 2:18, Rahul Rameshbabu wrote:

On Thu, 29 Jun, 2023 10:46:41 +0800 Zhengchao Shao [off-list ref] wrote:

quoted

The memory pointed to by the fs->any pointer is not freed in the error
path of mlx5e_fs_tt_redirect_any_create, which can lead to a memory leak.
Fix by freeing the memory in the error path, thereby making the error path
identical to mlx5e_fs_tt_redirect_any_destroy().

Fixes: 0f575c20bf06 ("net/mlx5e: Introduce Flow Steering ANY API")
Signed-off-by: Zhengchao Shao <redacted>
---
  drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c b/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c
index 03cb79adf912..9cf4ec931b8b 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c

@@ -594,7 +594,7 @@ int mlx5e_fs_tt_redirect_any_create(struct mlx5e_flow_steering *fs)
  
  	err = fs_any_create_table(fs);
  	if (err)
-		return err;
+		goto err_free_any;
  
  	err = fs_any_enable(fs);
  	if (err)

@@ -606,7 +606,7 @@ int mlx5e_fs_tt_redirect_any_create(struct mlx5e_flow_steering *fs)
  
  err_destroy_table:
  	fs_any_destroy_table(fs_any);
-
+err_free_any:
  	kfree(fs_any);
  	mlx5e_fs_set_any(fs, NULL);

Hi Rahul:

We probably should update the 'any' member reference in fs to NULL
*before* free-ing fs_any. Otherwise, there is a period in time where fs
is referring to a dirty pointer value in its any member field. It's not
critical, but it makes logical sense in my opinion. Lets swap these two
lines in this patch.

	It looks good. I will send V2. Thank you.

Zhengchao Shao

quoted

  	return err;

Thanks for the patch,

-- Rahul Rameshbabu