Re: [PATCH v2012.1] fs: symlink restrictions on sticky directories

From: Kees Cook
Date: Thu Jan 05 2012 - 14:36:11 EST


On Thu, Jan 5, 2012 at 1:17 AM, Ingo Molnar <mingo@xxxxxxx> wrote:
> * Kees Cook <keescook@xxxxxxxxxxxx> wrote:
>
>> @@ -1495,6 +1496,15 @@ static struct ctl_table fs_table[] = {
>>  #endif
>>  #endif
>>       {
>> +             .procname       = "protected_sticky_symlinks",
>> +             .data           = &protected_sticky_symlinks,
>> +             .maxlen         = sizeof(int),
>> +             .mode           = 0644,
>> +             .proc_handler   = proc_dointvec_minmax,
>> +             .extra1         = &zero,
>> +             .extra2         = &one,
>> +     },
>
> Small detail:
>
> Might make sense to change the .mode to 0600, to make it harder
> for unprivileged attack code to guess whether this protection
> (and the resulting audit warning to the administrator) is
> enabled on a system or not.

Sure, I have no problem with that. In addition to this change, what's
the best next step for this patch?

Thanks,

-Kees

--
Kees Cook
ChromeOS Security
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/