Re: [PATCH] net: sched: em_text: fix possible memory leak in em_text_destroy()

[Jamal Hadi Salim]

On Wed, Dec 20, 2023 at 6:55 AM Jamal Hadi Salim <jhs@xxxxxxxxxxxx> 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 PM Hangyu Hua <hbh25y@xxxxxxxxx> wrote:
> >
> > m->data needs to be freed when em_text_destroy is called.
> >
> > Fixes: d675c989ed2d ("[PKT_SCHED]: Packet classification based on textsearch (ematch)")
> > Signed-off-by: Hangyu Hua <hbh25y@xxxxxxxxx>
> > ---
> >  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);
> > +       }
> >  }
> >
>

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

cheers,
jamal
> Acked-by: Jamal Hadi Salim <jhs@xxxxxxxxxxxx>
>
> cheers,
> jamal
>
> >  static int em_text_dump(struct sk_buff *skb, struct tcf_ematch *m)
> > --
> > 2.34.1
> >