Re: [PATCH] net/mlx4_en: fix off by one in error handling

From: Tariq Toukan
Date: Wed Sep 14 2016 - 10:50:01 EST

On 14/09/2016 4:53 PM, Sebastian Ott wrote:
Hello Tariq,

On Wed, 14 Sep 2016, Tariq Toukan wrote:
On 14/09/2016 2:09 PM, Sebastian Ott wrote:
If an error occurs in mlx4_init_eq_table the index used in the
err_out_unmap label is one too big which results in a panic in
mlx4_free_eq. This patch fixes the index in the error path.
You are right, but your change below does not cover all cases.
The full solution looks like this:

@@ -1260,7 +1260,7 @@ int mlx4_init_eq_table(struct mlx4_dev *dev)
if (err)
- goto err_out_unmap;
+ goto err_out_unmap_excluded;
In this case a call to mlx4_create_eq failed. Do you really have to call
mlx4_free_eq for this index again?
We agree on this part, that's why here we should goto the _excluded_ label.
For all other parts, we should not exclude the eq in the highest index, and thus we goto the _non_excluded_ label.
As far as I understood this code
mlx4_create_eq cleans up when it fails and thus there is no need for an
additional mlx4_free_eq call.