Re: [PATCH] IB/sa: Fix memleak in ib_nl_make_request

[Leon Romanovsky <leon@kernel.org>]

On Sun, Dec 20, 2020 at 04:13:14PM +0800, Dinghao Liu wrote:
> When rdma_nl_multicast() fails, skb should be freed
> just like when ibnl_put_msg() fails.

It is not so simple as you wrote in the description.

There are no other places in the linux kernel that free
SKBs after netlink_multicast() failure.

Thanks

>
> Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
> ---
>  drivers/infiniband/core/sa_query.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c
> index 89a831fa1885..8bd23b5cc913 100644
> --- a/drivers/infiniband/core/sa_query.c
> +++ b/drivers/infiniband/core/sa_query.c
> @@ -873,8 +873,10 @@ static int ib_nl_make_request(struct ib_sa_query *query, gfp_t gfp_mask)
>  	spin_lock_irqsave(&ib_nl_request_lock, flags);
>  	ret = rdma_nl_multicast(&init_net, skb, RDMA_NL_GROUP_LS, gfp_flag);
>
> -	if (ret)
> +	if (ret) {
> +		nlmsg_free(skb);
>  		goto out;
> +	}
>
>  	/* Put the request on the list.*/
>  	delay = msecs_to_jiffies(sa_local_svc_timeout_ms);
> --
> 2.17.1
>