[Toybox] [PATCH] Fix find segfault.

[enh]

add tests?

On Sat, Sep 12, 2015 at 7:21 AM, Daniel K. Levy <alliedenvy at gmail.com> wrote:
> Okay, I found and fixed two different bugs in find.
>
> One, the -user, -group, -newer code branch during the action phase
> didn't pop off argdata when the check variable was false, causing the
> argdata list to get skewed vs. the filter. This led to -exec getting
> garbage off argdata and acting up. An example:
>
> $ ./toybox find -type f -user nobody -exec : \;
> find: bad arg ';'
>
> and bafflingly:
>
> $ ./toybox find -type f -user nobody -exec : -exec : \;
> Segmentation fault
>
> Two, the {} branch under -exec was running strcmp(ss[len+1], "+")
> without checking to make sure ss[len+1] wasn't null. So if you used {}
> and put nothing after, it would segfault.
>
> The -exec ls {} + still doesn't work, though. Is it broken, or just
> unimplemented?
>
> Patch follows.
>
> diff --git a/toys/posix/find.c b/toys/posix/find.c
> index 53aa2d9..f937942 100644
> --- a/toys/posix/find.c
> +++ b/toys/posix/find.c
> @@ -357,7 +357,7 @@ static int do_find(struct dirtree *new)
>              if (new->st.st_mtim.tv_sec == udl->u.tm.tv_sec)
>                test = new->st.st_mtim.tv_nsec > udl->u.tm.tv_nsec;
>            }
> -        }
> +        } else if (new) llist_pop(&argdata);
>        } else if (!strcmp(s, "exec") || !strcmp("ok", s)
>                || !strcmp(s, "execdir") || !strcmp(s, "okdir"))
>        {
> @@ -381,7 +381,7 @@ static int do_find(struct dirtree *new)
>              if (!strcmp(ss[len], ";")) break;
>              else if (!strcmp(ss[len], "{}")) {
>                aa->curly = len;
> -              if (!strcmp(ss[len+1], "+")) {
> +              if (ss[len+1] && !strcmp(ss[len+1], "+")) {
>
>                  // Measure environment space
>                  if (!TT.envsize) {
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-- 
Elliott Hughes - http://who/enh - http://jessies.org/~enh/
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