From: Leon Romanovsky <leon@kernel.org>
To: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Cc: dledford@redhat.com, jgg@ziepe.ca, linux-rdma@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] infiniband/core: Fix a use after free in cm_work_handler
Date: Thu, 11 Mar 2021 11:22:03 +0200 [thread overview]
Message-ID: <YEnhO9EXgI8pwVD2@unreal> (raw)
In-Reply-To: <20210311022153.3757-1-lyl2019@mail.ustc.edu.cn>
On Wed, Mar 10, 2021 at 06:21:53PM -0800, Lv Yunlong wrote:
> In cm_work_handler, it calls destory_cm_id() to release
> the initial reference of cm_id_priv taken by iw_create_cm_id()
> and free the cm_id_priv. After destory_cm_id(), iwcm_deref_id
> (cm_id_priv) will be called and cause a use after free.
>
> Fixes: 59c68ac31e15a ("iw_cm: free cm_id resources on the last deref")
> Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
> ---
> drivers/infiniband/core/iwcm.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/infiniband/core/iwcm.c b/drivers/infiniband/core/iwcm.c
> index da8adadf4755..cb6b4ac45e21 100644
> --- a/drivers/infiniband/core/iwcm.c
> +++ b/drivers/infiniband/core/iwcm.c
> @@ -1035,8 +1035,10 @@ static void cm_work_handler(struct work_struct *_work)
>
> if (!test_bit(IWCM_F_DROP_EVENTS, &cm_id_priv->flags)) {
> ret = process_event(cm_id_priv, &levent);
> - if (ret)
> + if (ret) {
> destroy_cm_id(&cm_id_priv->id);
> + return;
The destroy_cm_id() is called to free ->id and not cm_id_priv. This "return"
leaks cm_id_priv now and what "a use after free" do you see?
> + }
> } else
> pr_debug("dropping event %d\n", levent.event);
> if (iwcm_deref_id(cm_id_priv))
> --
> 2.25.1
>
>
next prev parent reply other threads:[~2021-03-11 9:22 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-11 2:21 [PATCH] infiniband/core: Fix a use after free in cm_work_handler Lv Yunlong
2021-03-11 9:22 ` Leon Romanovsky [this message]
2021-03-11 10:29 ` lyl2019
2021-03-11 11:05 ` Leon Romanovsky
2021-03-11 12:03 ` lyl2019
2021-03-11 14:12 ` Leon Romanovsky
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