Unpublished/android_kernel_samsung_t1 — pull request #3 by Unpublished (2014-06-17 14:37:49+00:00)
Title: futex-prevent-requeue-pi-on-same-futex.patch futex: Forbid uaddr == uadd...

...r2 in futex_requeue(..., requeue_pi=1)

If uaddr == uaddr2, then we have broken the rule of only requeueing from
a non-pi futex to a pi futex with this call. If we attempt this, then
dangling pointers may be left for rt_waiter resulting in an exploitable
condition.

This change brings futex_requeue() in line with futex_wait_requeue_pi()
which performs the same check as per commit 6f7b0a2a5c0f ("futex: Forbid
uaddr == uaddr2 in futex_wait_requeue_pi()")

[ tglx: Compare the resulting keys as well, as uaddrs might be
different depending on the mapping ]

Fixes CVE-2014-3153.

Change-Id: If140409eefcbcee299fe5ceeddc303ec86e61d2e
Reported-by: Pinkie Pie
Signed-off-by: Will Drewry
Signed-off-by: Kees Cook
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner
Reviewed-by: Darren Hart
Signed-off-by: Linus Torvalds