Messages in this thread | | | Date | Wed, 28 Mar 2012 23:24:07 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH] futex: do not leak robust list to unprivileged process |
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On Wed, 28 Mar 2012, Kees Cook wrote:
> On Thu, Mar 22, 2012 at 4:46 PM, Thomas Gleixner <tglx@linutronix.de> wrote: > > On Tue, 20 Mar 2012, Ingo Molnar wrote: > >> * Kees Cook <keescook@chromium.org> wrote: > >> > On Tue, Mar 20, 2012 at 10:02 AM, Thomas Gleixner <tglx@linutronix.de> wrote: > >> > > I really wonder why we have this syscall at all. > >> > > >> > The documentation I found yesterday while looking at this was: > >> > http://linux.die.net/man/2/get_robust_list > >> > > >> > Which says "The system call is only available for debugging > >> > purposes and is not needed for normal operations. Both system > >> > calls are not available to application programs as functions; > >> > they can be called using the syscall(3) function." > >> > > >> > Dropping the syscall entirely would certainly make it secure. > >> > ;) > >> > >> The thinking was API completeness. In general it's possible for > >> a sufficiently privileged task to figure out all the state of a > >> task. We can query timers, fds - the robust list is such a > >> resource as well. The information leakage was obviously not > >> intended. > > > > So I think it's safe to take Kees' patch as is. On top of that we > > should add a WARN_ONCE when the syscall is invoked and schedule the > > sucker for removal. > > Can someone claim the first patch? It looks like not everyone agrees > about removal, but I'd like to see at least the first one get in. :)
It's on my list for tomorrow.
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