Re: [PATCH 3/5] v2 seccomp_filters: Enable ftrace-based system call filtering

david
2011-05-26T18:35:23Z

On Thu, 26 May 2011, Linus Torvalds wrote:
>
> On Thu, May 26, 2011 at 9:33 AM, Will Drewry <wad@chromium.org> wrote:
>>
>> FWIW, none of the patches deal with privilege escalation via setuid
>> files or file capabilities.
>
> That is NOT AT ALL what I'm talking about.
>
> I'm talking about the "setuid()" system call (and all its cousins:
> setgit/setreuid etc). And the whole thread has been about filtering
> system calls, no?
>
> Do a google code search for setuid.
>
> In good code, it will look something like
>
> uid = getuid();
>
> if (setuid(uid)) {
> fprintf(stderr, "Unable to drop provileges\n");
> exit(1);
> }
>
> but I guarantee you that there are cases where people just blindly
> drop privileges. google code search found me at least the "heirloom"
> source code doing exactly that.

I believe that sendmail had this exact vunerability when capibilities were
used to control setuid a couple of years ago.

David Lang