On Tue, 30 Aug 2016 18:46:23 -0400 Kees Cook <[email protected]> wrote:
> On Mon, Aug 22, 2016 at 7:01 PM, John Stultz <[email protected]> wrote: > > In changing from checking ptrace_may_access(p, PTRACE_MODE_ATTACH_FSCREDS) > > to capable(CAP_SYS_NICE), I missed that ptrace_my_access succeeds > > when p == current, but the CAP_SYS_NICE doesn't. > > > > Thus while the previous commit was intended to loosen the needed > > privledges to modify a processes timerslack, it needlessly restricted > > a task modifying its own timerslack via the proc/<tid>/timerslack_ns > > (which is permitted also via the PR_SET_TIMERSLACK method). > > > > This patch corrects this by checking if p == current before checking > > the CAP_SYS_NICE value. > > > > This patch applies on top of my two previous patches currently in -mm > > > > Cc: Kees Cook <[email protected]> > > Cc: "Serge E. Hallyn" <[email protected]> > > Cc: Andrew Morton <[email protected]> > > Cc: Thomas Gleixner <[email protected]> > > CC: Arjan van de Ven <[email protected]> > > Cc: Oren Laadan <[email protected]> > > Cc: Ruchi Kandoi <[email protected]> > > Cc: Rom Lemarchand <[email protected]> > > Cc: Todd Kjos <[email protected]> > > Cc: Colin Cross <[email protected]> > > Cc: Nick Kralevich <[email protected]> > > Cc: Dmitry Shmidt <[email protected]> > > Cc: Elliott Hughes <[email protected]> > > Cc: Android Kernel Team <[email protected]> > > Acked-by: Kees Cook <[email protected]> > > Signed-off-by: John Stultz <[email protected]> > > Andrew, can you take this for v4.8? Well, it fixes proc-relax-proc-tid-timerslack_ns-capability-requirements.patch, somewhat. And it textually depends on that. Do we want all of proc-relax-proc-tid-timerslack_ns-capability-requirements.patch proc-add-lsm-hook-checks-to-proc-tid-timerslack_ns.patch proc-fix-timerslack_ns-cap_sys_nice-check-when-adjusting-self.patch in 4.8? If so, why?
