patches/kernel/0031-x86-entry-Fix-idtentry-unwind-hint.patch

   1 From b368fed558634ffc92dba0d7d9e4e631d26cd92f Mon Sep 17 00:00:00 2001
   2 From: Josh Poimboeuf <jpoimboe@redhat.com>
   3 Date: Fri, 20 Oct 2017 11:21:33 -0500
   4 Subject: [PATCH 031/241] x86/entry: Fix idtentry unwind hint
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 CVE-2017-5754
  10
  11 This fixes the following ORC warning in the 'int3' entry code:
  12
  13   WARNING: can't dereference iret registers at ffff8801c5f17fe0 for ip ffffffff95f0d94b
  14
  15 The ORC metadata had the wrong stack offset for the iret registers.
  16
  17 Their location on the stack is dependent on whether the exception has an
  18 error code.
  19
  20 Reported-and-tested-by: Andrei Vagin <avagin@virtuozzo.com>
  21 Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
  22 Cc: Andy Lutomirski <luto@kernel.org>
  23 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  24 Cc: Peter Zijlstra <peterz@infradead.org>
  25 Cc: Thomas Gleixner <tglx@linutronix.de>
  26 Fixes: 8c1f75587a18 ("x86/entry/64: Add unwind hint annotations")
  27 Link: http://lkml.kernel.org/r/931d57f0551ed7979d5e7e05370d445c8e5137f8.1508516398.git.jpoimboe@redhat.com
  28 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  29 (cherry picked from commit 98990a33b77dda9babf91cb235654f6729e5702e)
  30 Signed-off-by: Andy Whitcroft <apw@canonical.com>
  31 Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
  32 (cherry picked from commit 266be2a5053230f6d0b6f27d3e8e9f28df40dd7e)
  33 Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
  34 ---
  35  arch/x86/entry/entry_64.S | 2 +-
  36  1 file changed, 1 insertion(+), 1 deletion(-)
  37
  38 diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
  39 index c12260ef3e4b..2e4fc6425f47 100644
  40 --- a/arch/x86/entry/entry_64.S
  41 +++ b/arch/x86/entry/entry_64.S
  42 @@ -821,7 +821,7 @@ apicinterrupt IRQ_WORK_VECTOR                       irq_work_interrupt              smp_irq_work_interrupt
  43
  44  .macro idtentry sym do_sym has_error_code:req paranoid=0 shift_ist=-1
  45  ENTRY(\sym)
  46 -       UNWIND_HINT_IRET_REGS offset=8
  47 +       UNWIND_HINT_IRET_REGS offset=\has_error_code*8
  48
  49         /* Sanity check */
  50         .if \shift_ist != -1 && \paranoid == 0
  51 --
  52 2.14.2
  53