Re: [PATCH] Prevent normalize() from reading into undefined memory

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Sun, Jan 08, 2023 at 04:55:59PM -0800, Ian Rogers escreveu:
> On Sun, Jan 8, 2023, 6:13 AM Jiri Olsa <olsajiri@gmail.com> wrote:
> 
> > On Sun, Dec 04, 2022 at 04:28:35PM +0530, Sohom Datta wrote:
> > > The current implementation does not account for a
> > > trailing backslash followed by a null-byte. If a
> > > null-byte is encountered following a backslash,
> > > normalize() will continue reading (and potentially
> > > writing) into garbage memory ignoring the EOS
> > > null-byte.
> > >
> > > Signed-off-by: Sohom Datta <sohomdatta1+git@gmail.com>
> >
> > Acked-by: Jiri Olsa <jolsa@kernel.org>
> >
> > thanks,
> > jirka
> >
> 
> Acked-by: Ian Rogers <irogers@google.com>

Thanks, applied. Sorry for the delay, probably I didn't saw the "perf
tools: ' prefix in the subject and this fell thru the cracks :-\

Thanks to Ingo for pinging me about this, appreciated.

- Arnaldo
 
> Thanks,
> Ian
> 
> > ---
> > >  tools/perf/util/expr.l | 5 ++++-
> > >  1 file changed, 4 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/tools/perf/util/expr.l b/tools/perf/util/expr.l
> > > index 0168a9637330..d47de5f270a8 100644
> > > --- a/tools/perf/util/expr.l
> > > +++ b/tools/perf/util/expr.l
> > > @@ -42,8 +42,11 @@ static char *normalize(char *str, int runtime)
> > >       char *dst = str;
> > >
> > >       while (*str) {
> > > -             if (*str == '\\')
> > > +             if (*str == '\\') {
> > >                       *dst++ = *++str;
> > > +                     if (!*str)
> > > +                             break;
> > > +             }
> > >               else if (*str == '?') {
> > >                       char *paramval;
> > >                       int i = 0;
> > > --
> > > 2.38.1
> > >
> >