patches/kernel/0168-arch-mm-Allow-arch_dup_mmap-to-fail.patch

   1 From 45f502dae27e55fa46c65e71c226eec759ea7385 Mon Sep 17 00:00:00 2001
   2 From: Thomas Gleixner <tglx@linutronix.de>
   3 Date: Thu, 14 Dec 2017 12:27:29 +0100
   4 Subject: [PATCH 168/233] arch, mm: Allow arch_dup_mmap() to fail
   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 In order to sanitize the LDT initialization on x86 arch_dup_mmap() must be
  12 allowed to fail. Fix up all instances.
  13
  14 Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
  15 Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
  16 Cc: Andy Lutomirski <luto@kernel.org>
  17 Cc: Andy Lutomirsky <luto@kernel.org>
  18 Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
  19 Cc: Borislav Petkov <bp@alien8.de>
  20 Cc: Borislav Petkov <bpetkov@suse.de>
  21 Cc: Brian Gerst <brgerst@gmail.com>
  22 Cc: Dave Hansen <dave.hansen@intel.com>
  23 Cc: Dave Hansen <dave.hansen@linux.intel.com>
  24 Cc: David Laight <David.Laight@aculab.com>
  25 Cc: Denys Vlasenko <dvlasenk@redhat.com>
  26 Cc: Eduardo Valentin <eduval@amazon.com>
  27 Cc: Greg KH <gregkh@linuxfoundation.org>
  28 Cc: H. Peter Anvin <hpa@zytor.com>
  29 Cc: Josh Poimboeuf <jpoimboe@redhat.com>
  30 Cc: Juergen Gross <jgross@suse.com>
  31 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  32 Cc: Peter Zijlstra <peterz@infradead.org>
  33 Cc: Will Deacon <will.deacon@arm.com>
  34 Cc: aliguori@amazon.com
  35 Cc: dan.j.williams@intel.com
  36 Cc: hughd@google.com
  37 Cc: keescook@google.com
  38 Cc: kirill.shutemov@linux.intel.com
  39 Cc: linux-mm@kvack.org
  40 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  41 (cherry picked from commit c10e83f598d08046dd1ebc8360d4bb12d802d51b)
  42 Signed-off-by: Andy Whitcroft <apw@canonical.com>
  43 Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
  44 (cherry picked from commit b812abb61437eda1f5718a95085d67902f813f2f)
  45 Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
  46 ---
  47  arch/powerpc/include/asm/mmu_context.h   | 5 +++--
  48  arch/um/include/asm/mmu_context.h        | 3 ++-
  49  arch/unicore32/include/asm/mmu_context.h | 5 +++--
  50  arch/x86/include/asm/mmu_context.h       | 4 ++--
  51  include/asm-generic/mm_hooks.h           | 5 +++--
  52  kernel/fork.c                            | 3 +--
  53  6 files changed, 14 insertions(+), 11 deletions(-)
  54
  55 diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
  56 index 35bec1c5bd5a..60afcc94e673 100644
  57 --- a/arch/powerpc/include/asm/mmu_context.h
  58 +++ b/arch/powerpc/include/asm/mmu_context.h
  59 @@ -185,9 +185,10 @@ static inline void enter_lazy_tlb(struct mm_struct *mm,
  60  #endif
  61  }
  62
  63 -static inline void arch_dup_mmap(struct mm_struct *oldmm,
  64 -                                struct mm_struct *mm)
  65 +static inline int arch_dup_mmap(struct mm_struct *oldmm,
  66 +                               struct mm_struct *mm)
  67  {
  68 +       return 0;
  69  }
  70
  71  static inline void arch_exit_mmap(struct mm_struct *mm)
  72 diff --git a/arch/um/include/asm/mmu_context.h b/arch/um/include/asm/mmu_context.h
  73 index b668e351fd6c..fca34b2177e2 100644
  74 --- a/arch/um/include/asm/mmu_context.h
  75 +++ b/arch/um/include/asm/mmu_context.h
  76 @@ -15,9 +15,10 @@ extern void uml_setup_stubs(struct mm_struct *mm);
  77  /*
  78   * Needed since we do not use the asm-generic/mm_hooks.h:
  79   */
  80 -static inline void arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
  81 +static inline int arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
  82  {
  83         uml_setup_stubs(mm);
  84 +       return 0;
  85  }
  86  extern void arch_exit_mmap(struct mm_struct *mm);
  87  static inline void arch_unmap(struct mm_struct *mm,
  88 diff --git a/arch/unicore32/include/asm/mmu_context.h b/arch/unicore32/include/asm/mmu_context.h
  89 index 59b06b48f27d..5c205a9cb5a6 100644
  90 --- a/arch/unicore32/include/asm/mmu_context.h
  91 +++ b/arch/unicore32/include/asm/mmu_context.h
  92 @@ -81,9 +81,10 @@ do { \
  93         } \
  94  } while (0)
  95
  96 -static inline void arch_dup_mmap(struct mm_struct *oldmm,
  97 -                                struct mm_struct *mm)
  98 +static inline int arch_dup_mmap(struct mm_struct *oldmm,
  99 +                               struct mm_struct *mm)
 100  {
 101 +       return 0;
 102  }
 103
 104  static inline void arch_unmap(struct mm_struct *mm,
 105 diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
 106 index efc530642f7d..9be54d9c04c4 100644
 107 --- a/arch/x86/include/asm/mmu_context.h
 108 +++ b/arch/x86/include/asm/mmu_context.h
 109 @@ -175,10 +175,10 @@ do {                                              \
 110  } while (0)
 111  #endif
 112
 113 -static inline void arch_dup_mmap(struct mm_struct *oldmm,
 114 -                                struct mm_struct *mm)
 115 +static inline int arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
 116  {
 117         paravirt_arch_dup_mmap(oldmm, mm);
 118 +       return 0;
 119  }
 120
 121  static inline void arch_exit_mmap(struct mm_struct *mm)
 122 diff --git a/include/asm-generic/mm_hooks.h b/include/asm-generic/mm_hooks.h
 123 index 41e5b6784b97..7a2980f4e3e6 100644
 124 --- a/include/asm-generic/mm_hooks.h
 125 +++ b/include/asm-generic/mm_hooks.h
 126 @@ -6,9 +6,10 @@
 127  #ifndef _ASM_GENERIC_MM_HOOKS_H
 128  #define _ASM_GENERIC_MM_HOOKS_H
 129
 130 -static inline void arch_dup_mmap(struct mm_struct *oldmm,
 131 -                                struct mm_struct *mm)
 132 +static inline int arch_dup_mmap(struct mm_struct *oldmm,
 133 +                               struct mm_struct *mm)
 134  {
 135 +       return 0;
 136  }
 137
 138  static inline void arch_exit_mmap(struct mm_struct *mm)
 139 diff --git a/kernel/fork.c b/kernel/fork.c
 140 index 8efc6b4466e3..1d907772b9d2 100644
 141 --- a/kernel/fork.c
 142 +++ b/kernel/fork.c
 143 @@ -712,8 +712,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
 144                         goto out;
 145         }
 146         /* a new mm has just been created */
 147 -       arch_dup_mmap(oldmm, mm);
 148 -       retval = 0;
 149 +       retval = arch_dup_mmap(oldmm, mm);
 150  out:
 151         up_write(&mm->mmap_sem);
 152         flush_tlb_mm(oldmm);
 153 --
 154 2.14.2
 155