Re: [PATCH 1/2] NTB: fix access of free-ed pointer

From: Jon Mason
Date: Sun Oct 04 2015 - 22:37:57 EST


On Sat, Oct 3, 2015 at 4:09 AM, Sudip Mukherjee
<sudipm.mukherjee@xxxxxxxxx> wrote:
> We were accessing nt->mw_vec after freeing it. Fix the error path so
> that we free nt->mw_vec after we have finished using it.
>
> Signed-off-by: Sudip Mukherjee <sudip@xxxxxxxxxxxxxxx>

Good catch. Pulled into my ntb branch.

Thanks,
Jon


> ---
> drivers/ntb/ntb_transport.c | 15 +++++++--------
> 1 file changed, 7 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
> index 6e3ee90..69953ee 100644
> --- a/drivers/ntb/ntb_transport.c
> +++ b/drivers/ntb/ntb_transport.c
> @@ -1080,7 +1080,7 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
> GFP_KERNEL, node);
> if (!nt->qp_vec) {
> rc = -ENOMEM;
> - goto err2;
> + goto err1;
> }
>
> if (nt_debugfs_dir) {
> @@ -1092,7 +1092,7 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
> for (i = 0; i < qp_count; i++) {
> rc = ntb_transport_init_queue(nt, i);
> if (rc)
> - goto err3;
> + goto err2;
> }
>
> INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
> @@ -1100,12 +1100,12 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
>
> rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
> if (rc)
> - goto err3;
> + goto err2;
>
> INIT_LIST_HEAD(&nt->client_devs);
> rc = ntb_bus_init(nt);
> if (rc)
> - goto err4;
> + goto err3;
>
> nt->link_is_up = false;
> ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
> @@ -1113,17 +1113,16 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
>
> return 0;
>
> -err4:
> - ntb_clear_ctx(ndev);
> err3:
> - kfree(nt->qp_vec);
> + ntb_clear_ctx(ndev);
> err2:
> - kfree(nt->mw_vec);
> + kfree(nt->qp_vec);
> err1:
> while (i--) {
> mw = &nt->mw_vec[i];
> iounmap(mw->vbase);
> }
> + kfree(nt->mw_vec);
> err:
> kfree(nt);
> return rc;
> --
> 1.9.1
>
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