Re: [PATCH v1 1/3] lib subcmd: Fix memory leak in uniq

From: Arnaldo Carvalho de Melo
Date: Thu Jan 04 2024 - 16:03:20 EST


Em Tue, Jan 02, 2024 at 11:30:39AM -0800, Ian Rogers escreveu:
> On Thu, Dec 7, 2023 at 4:05 PM Ian Rogers <irogers@xxxxxxxxxx> wrote:
> >
> > uniq will write one command name over another causing the overwritten
> > string to be leaked. Fix by doing a pass that removes duplicates and a
> > second that removes the holes.
> >
> > Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
>
> Ping for this series, no comments since sent.

I applied the first one, the fix for uniq(), but somehow the second
didn't work for me as in your examples, nor the third, the output is the
same as before.

- Arnaldo

> Thanks,
> Ian
>
> > ---
> > tools/lib/subcmd/help.c | 18 ++++++++++++++----
> > 1 file changed, 14 insertions(+), 4 deletions(-)
> >
> > diff --git a/tools/lib/subcmd/help.c b/tools/lib/subcmd/help.c
> > index adfbae27dc36..8561b0f01a24 100644
> > --- a/tools/lib/subcmd/help.c
> > +++ b/tools/lib/subcmd/help.c
> > @@ -52,11 +52,21 @@ void uniq(struct cmdnames *cmds)
> > if (!cmds->cnt)
> > return;
> >
> > - for (i = j = 1; i < cmds->cnt; i++)
> > - if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
> > - cmds->names[j++] = cmds->names[i];
> > -
> > + for (i = 1; i < cmds->cnt; i++) {
> > + if (!strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
> > + zfree(&cmds->names[i - 1]);
> > + }
> > + for (i = 0, j = 0; i < cmds->cnt; i++) {
> > + if (cmds->names[i]) {
> > + if (i == j)
> > + j++;
> > + else
> > + cmds->names[j++] = cmds->names[i];
> > + }
> > + }
> > cmds->cnt = j;
> > + while (j < i)
> > + cmds->names[j++] = NULL;
> > }
> >
> > void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
> > --
> > 2.43.0.472.g3155946c3a-goog
> >
>

--

- Arnaldo