2021-11-04 10:17:10

by Jiasheng Jiang

Subject: [PATCH] RDMA/mlx4: Fix potential memory leak

In the error path, the dev->dev isn't released.
Therefore, it might be better to fix it to avoid
potential memory leak.

Fixes: 9376932 ("IB/mlx4_ib: Add support for user MR re-registration")
Signed-off-by: Jiasheng Jiang <[email protected]>
---
drivers/infiniband/hw/mlx4/mr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/mlx4/mr.c b/drivers/infiniband/hw/mlx4/mr.c
index 50becc0..d8ae92e 100644
--- a/drivers/infiniband/hw/mlx4/mr.c
+++ b/drivers/infiniband/hw/mlx4/mr.c
@@ -473,7 +473,7 @@ struct ib_mr *mlx4_ib_rereg_user_mr(struct ib_mr *mr, int flags, u64 start,
*/
err = mlx4_mr_hw_get_mpt(dev->dev, &mmr->mmr, &pmpt_entry);
if (err)
- return ERR_PTR(err);
+ goto release_mpt_entry;

if (flags & IB_MR_REREG_PD) {
err = mlx4_mr_hw_change_pd(dev->dev, *pmpt_entry,
--
2.7.4

2021-11-07 16:46:56

by Leon Romanovsky

Subject: Re: [PATCH] RDMA/mlx4: Fix potential memory leak

On Thu, Nov 04, 2021 at 10:14:12AM +0000, Jiasheng Jiang wrote:
> In the error path, the dev->dev isn't released.
> Therefore, it might be better to fix it to avoid
> potential memory leak.
>
> Fixes: 9376932 ("IB/mlx4_ib: Add support for user MR re-registration")
> Signed-off-by: Jiasheng Jiang <[email protected]>
> ---
> drivers/infiniband/hw/mlx4/mr.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

I don't understand about which release you are talking, but this patch
can't be right. You are supposed to call to "release_mpt_entry" only in
the error flows which after successful mlx4_mr_hw_get_mpt().

Thanks

>
> diff --git a/drivers/infiniband/hw/mlx4/mr.c b/drivers/infiniband/hw/mlx4/mr.c
> index 50becc0..d8ae92e 100644
> --- a/drivers/infiniband/hw/mlx4/mr.c
> +++ b/drivers/infiniband/hw/mlx4/mr.c
> @@ -473,7 +473,7 @@ struct ib_mr *mlx4_ib_rereg_user_mr(struct ib_mr *mr, int flags, u64 start,
> */
> err = mlx4_mr_hw_get_mpt(dev->dev, &mmr->mmr, &pmpt_entry);
> if (err)
> - return ERR_PTR(err);
> + goto release_mpt_entry;
>
> if (flags & IB_MR_REREG_PD) {
> err = mlx4_mr_hw_change_pd(dev->dev, *pmpt_entry,
> --
> 2.7.4
>