linux-kernel - Re: [PATCH v2] perf: fix double free at function perf_hpp__reset_output

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20170411103249.GA29545@krava>
Date:   Tue, 11 Apr 2017 12:32:49 +0200
From:   Jiri Olsa <jolsa@...hat.com>
To:     "Du, Changbin" <changbin.du@...el.com>
Cc:     Arnaldo Carvalho de Melo <acme@...nel.org>,
        Namhyung Kim <namhyung@...nel.org>,
        Jiri Olsa <jolsa@...nel.org>, peterz@...radead.org,
        mingo@...hat.com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] perf: fix double free at function
 perf_hpp__reset_output_field

On Tue, Apr 11, 2017 at 06:13:17PM +0800, Du, Changbin wrote:
> > > >  
> > > yes, this is an option. But for safety, I sugguest do not rely on list_del_init.
> > > No rule rather than create one.
> > > 
> > > But anyway, both are ok for me. What's your options?
> > 
> > hum, also I dont think we need to touch that bit at all
> > if we are going to remove it right away.. how about the
> > change below?
> > 
> > jirka
> > 
> > 
> > ---
> > diff --git a/tools/perf/ui/hist.c b/tools/perf/ui/hist.c
> > index 5d632dca672a..0ee7db43dd7d 100644
> > --- a/tools/perf/ui/hist.c
> > +++ b/tools/perf/ui/hist.c
> > @@ -613,15 +613,15 @@ void perf_hpp__reset_output_field(struct perf_hpp_list *list)
> >  
> >  	/* reset output fields */
> >  	perf_hpp_list__for_each_format_safe(list, fmt, tmp) {
> > -		list_del_init(&fmt->list);
> > -		list_del_init(&fmt->sort_list);
> > +		list_del(&fmt->list);
> > +		/* Remove the fmt from next loop processing. */
> > +		list_del(&fmt->sort_list);
> >  		fmt_free(fmt);
> What if the fmt is not linked to sort_list? I see it is possible (please
> checking perf_hpp__setup_output_field()). I am not sure if we really has
> sunch case currently, just concern :)

if it's not linked to sort_list, then sort_list is initialized
and list_del should do no harm

jirka