Re: [patch] IB/cma: allocating too much memory in make_cma_ports()

From: Matan Barak
Date: Tue Jan 12 2016 - 08:08:39 EST


On Tue, Jan 12, 2016 at 11:29 AM, Dan Carpenter
<dan.carpenter@xxxxxxxxxx> wrote:
> The issue here is that there is a cut and paste bug. When we allocate
> cma_dev_group->default_ports_group we use "sizeof(*cma_dev_group->ports)"
> instead of "sizeof(*cma_dev_group->default_ports_group)".
>
> We're bumping up against the 80 character limit so I introduced a new
> local pointer "ports_group" to get around that.
>
> Fixes: 045959db65c6 ('IB/cma: Add configfs for rdma_cm')
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> ---
> Not tested.
>
> diff --git a/drivers/infiniband/core/cma_configfs.c b/drivers/infiniband/core/cma_configfs.c
> index bd1d640..18b112a 100644
> --- a/drivers/infiniband/core/cma_configfs.c
> +++ b/drivers/infiniband/core/cma_configfs.c
> @@ -158,6 +158,7 @@ static int make_cma_ports(struct cma_dev_group *cma_dev_group,
> unsigned int i;
> unsigned int ports_num;
> struct cma_dev_port_group *ports;
> + struct config_group **ports_group;
> int err;
>
> ibdev = cma_get_ib_dev(cma_dev);
> @@ -168,12 +169,9 @@ static int make_cma_ports(struct cma_dev_group *cma_dev_group,
> ports_num = ibdev->phys_port_cnt;
> ports = kcalloc(ports_num, sizeof(*cma_dev_group->ports),
> GFP_KERNEL);
> + ports_group = kcalloc(ports_num + 1, sizeof(*ports_group), GFP_KERNEL);
>
> - cma_dev_group->default_ports_group = kcalloc(ports_num + 1,
> - sizeof(*cma_dev_group->ports),
> - GFP_KERNEL);
> -
> - if (!ports || !cma_dev_group->default_ports_group) {
> + if (!ports || !ports_group) {
> err = -ENOMEM;
> goto free;
> }
> @@ -187,15 +185,16 @@ static int make_cma_ports(struct cma_dev_group *cma_dev_group,
> config_group_init_type_name(&ports[i].group,
> port_str,
> &cma_port_group_type);
> - cma_dev_group->default_ports_group[i] = &ports[i].group;
> + ports_group[i] = &ports[i].group;
> }
> - cma_dev_group->default_ports_group[i] = NULL;
> + ports_group[i] = NULL;
> + cma_dev_group->default_ports_group = ports_group;
> cma_dev_group->ports = ports;
>
> return 0;
> free:
> kfree(ports);
> - kfree(cma_dev_group->default_ports_group);
> + kfree(ports_group);
> cma_dev_group->ports = NULL;
> cma_dev_group->default_ports_group = NULL;
> return err;
> --
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Hi,

This is already fixed in [1].
Anyway, I'm fine with either one of them.

Acked-by: Matan Barak <matanb@xxxxxxxxxxxx>

Regards,
Matan

[1] http://www.spinics.net/lists/linux-rdma/msg32152.html