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From: Jamal Hadi Salim <jhs@mojatatu.com>
Date: Wed, 20 Dec 2023 11:05:55 -0500
Message-ID: <CAM0EoM=4ZRteGbjAdBuLGtbM_qpnJoUuky-Yj+i+3FOqXXra+Q@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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On Wed, Dec 20, 2023 at 6:55=E2=80=AFAM Jamal Hadi Salim <jhs@mojatatu.com>=
 wrote:
>
> 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> wr=
ote:
> >
> > m->data needs to be freed when em_text_destroy is called.
> >
> > Fixes: d675c989ed2d ("[PKT_SCHED]: Packet classification based on texts=
earch (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 *dat=
a, 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);
> > +       }
> >  }
> >
>

the bot just complained about needing a cast, use this:
struct text_match *

cheers,
jamal
> 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
> >