patches/kernel/0201-x86-mm-pti-Map-ESPFIX-into-user-space.patch

   1 From 9378cf5830b41fc4659335da883d2a1d52fe0661 Mon Sep 17 00:00:00 2001
   2 From: Andy Lutomirski <luto@kernel.org>
   3 Date: Fri, 15 Dec 2017 22:08:18 +0100
   4 Subject: [PATCH 201/233] x86/mm/pti: Map ESPFIX into user space
   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 Map the ESPFIX pages into user space when PTI is enabled.
  12
  13 Signed-off-by: Andy Lutomirski <luto@kernel.org>
  14 Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
  15 Cc: Borislav Petkov <bp@alien8.de>
  16 Cc: Brian Gerst <brgerst@gmail.com>
  17 Cc: Dave Hansen <dave.hansen@linux.intel.com>
  18 Cc: David Laight <David.Laight@aculab.com>
  19 Cc: H. Peter Anvin <hpa@zytor.com>
  20 Cc: Josh Poimboeuf <jpoimboe@redhat.com>
  21 Cc: Juergen Gross <jgross@suse.com>
  22 Cc: Kees Cook <keescook@chromium.org>
  23 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  24 Cc: Peter Zijlstra <peterz@infradead.org>
  25 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  26 (cherry picked from commit 4b6bbe95b87966ba08999574db65c93c5e925a36)
  27 Signed-off-by: Andy Whitcroft <apw@canonical.com>
  28 Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
  29 (cherry picked from commit f5103cc3035ae6d1816404696ee2eb06d53b6709)
  30 Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
  31 ---
  32  arch/x86/mm/pti.c | 11 +++++++++++
  33  1 file changed, 11 insertions(+)
  34
  35 diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c
  36 index 0e78797650a7..b1c38ef9fbbb 100644
  37 --- a/arch/x86/mm/pti.c
  38 +++ b/arch/x86/mm/pti.c
  39 @@ -287,6 +287,16 @@ static void __init pti_clone_user_shared(void)
  40         pti_clone_p4d(CPU_ENTRY_AREA_BASE);
  41  }
  42
  43 +/*
  44 + * Clone the ESPFIX P4D into the user space visinble page table
  45 + */
  46 +static void __init pti_setup_espfix64(void)
  47 +{
  48 +#ifdef CONFIG_X86_ESPFIX64
  49 +       pti_clone_p4d(ESPFIX_BASE_ADDR);
  50 +#endif
  51 +}
  52 +
  53  /*
  54   * Clone the populated PMDs of the entry and irqentry text and force it RO.
  55   */
  56 @@ -308,4 +318,5 @@ void __init pti_init(void)
  57
  58         pti_clone_user_shared();
  59         pti_clone_entry_text();
  60 +       pti_setup_espfix64();
  61  }
  62 --
  63 2.14.2
  64