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From: Jamal Hadi Salim <jhs@mojatatu.com>
Date: Wed, 20 Dec 2023 06:55:39 -0500
Message-ID: <CAM0EoMnPgKFK5uyx5YJUYc1F7U0058aYOQb6H6ewcz9Y8OouAw@mail.gmail.com>
Subject: Re: [PATCH] net: sched: em_text: fix possible memory leak in em_text_destroy()
To: Hangyu Hua <hbh25y@gmail.com>
Cc: xiyou.wangcong@gmail.com, jiri@resnulli.us, davem@davemloft.net, 
	edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, tgraf@suug.ch, 
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
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Hi Hangyu,
While the fix looks correct - can you please describe how you came
across this issue? Was it a tool or by inspection? Do you have a text
case that triggered something etc, etc.

On Tue, Dec 19, 2023 at 10:09=E2=80=AFPM Hangyu Hua <hbh25y@gmail.com> wrot=
e:
>
> m->data needs to be freed when em_text_destroy is called.
>
> Fixes: d675c989ed2d ("[PKT_SCHED]: Packet classification based on textsea=
rch (ematch)")
> Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
> ---
>  net/sched/em_text.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/net/sched/em_text.c b/net/sched/em_text.c
> index 6f3c1fb2fb44..b9d5d4dca2c9 100644
> --- a/net/sched/em_text.c
> +++ b/net/sched/em_text.c
> @@ -97,8 +97,10 @@ static int em_text_change(struct net *net, void *data,=
 int len,
>
>  static void em_text_destroy(struct tcf_ematch *m)
>  {
> -       if (EM_TEXT_PRIV(m) && EM_TEXT_PRIV(m)->config)
> +       if (EM_TEXT_PRIV(m) && EM_TEXT_PRIV(m)->config) {
>                 textsearch_destroy(EM_TEXT_PRIV(m)->config);
> +               kfree(m->data);
> +       }
>  }
>

Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>

cheers,
jamal

>  static int em_text_dump(struct sk_buff *skb, struct tcf_ematch *m)
> --
> 2.34.1
>