patches/kernel/0099-x86-entry-Add-task_top_of_stack-to-find-the-top-of-a.patch

   1 From 181d224dabca9a9061a6955cf3d49a4eba7294bf Mon Sep 17 00:00:00 2001
   2 From: Andy Lutomirski <luto@kernel.org>
   3 Date: Thu, 2 Nov 2017 00:59:11 -0700
   4 Subject: [PATCH 099/233] x86/entry: Add task_top_of_stack() to find the top of
   5  a task's stack
   6 MIME-Version: 1.0
   7 Content-Type: text/plain; charset=UTF-8
   8 Content-Transfer-Encoding: 8bit
   9
  10 CVE-2017-5754
  11
  12 This will let us get rid of a few places that hardcode accesses to
  13 thread.sp0.
  14
  15 Signed-off-by: Andy Lutomirski <luto@kernel.org>
  16 Cc: Borislav Petkov <bpetkov@suse.de>
  17 Cc: Brian Gerst <brgerst@gmail.com>
  18 Cc: Dave Hansen <dave.hansen@intel.com>
  19 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  20 Cc: Peter Zijlstra <peterz@infradead.org>
  21 Cc: Thomas Gleixner <tglx@linutronix.de>
  22 Link: http://lkml.kernel.org/r/b49b3f95a8ff858c40c9b0f5b32be0355324327d.1509609304.git.luto@kernel.org
  23 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  24 (cherry picked from commit 3500130b84a3cdc5b6796eba1daf178944935efe)
  25 Signed-off-by: Andy Whitcroft <apw@canonical.com>
  26 Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
  27 (cherry picked from commit f1078e10e361afaeb22ee72c54d5ad397e19728d)
  28 Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
  29 ---
  30  arch/x86/include/asm/processor.h | 2 ++
  31  1 file changed, 2 insertions(+)
  32
  33 diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
  34 index 85ddfc1a9bb5..f83fbf1b6dd9 100644
  35 --- a/arch/x86/include/asm/processor.h
  36 +++ b/arch/x86/include/asm/processor.h
  37 @@ -788,6 +788,8 @@ static inline void spin_lock_prefetch(const void *x)
  38  #define TOP_OF_INIT_STACK ((unsigned long)&init_stack + sizeof(init_stack) - \
  39                            TOP_OF_KERNEL_STACK_PADDING)
  40
  41 +#define task_top_of_stack(task) ((unsigned long)(task_pt_regs(task) + 1))
  42 +
  43  #ifdef CONFIG_X86_32
  44  /*
  45   * User space process size: 3GB (default).
  46 --
  47 2.14.2
  48