patches/kernel/0116-selftests-x86-ldt_get-Add-a-few-additional-tests-for.patch

   1 From 26e89424fe3c13d437f960736a7b925f3953cad6 Mon Sep 17 00:00:00 2001
   2 From: Andy Lutomirski <luto@kernel.org>
   3 Date: Sat, 4 Nov 2017 04:19:52 -0700
   4 Subject: [PATCH 116/241] selftests/x86/ldt_get: Add a few additional tests for
   5  limits
   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 We weren't testing the .limit and .limit_in_pages fields very well.
  13 Add more tests.
  14
  15 This addition seems to trigger the "bits 16:19 are undefined" issue
  16 that was fixed in an earlier patch.  I think that, at least on my
  17 CPU, the high nibble of the limit ends in LAR bits 16:19.
  18
  19 Signed-off-by: Andy Lutomirski <luto@kernel.org>
  20 Cc: Borislav Petkov <bpetkov@suse.de>
  21 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  22 Cc: Peter Zijlstra <peterz@infradead.org>
  23 Cc: Thomas Gleixner <tglx@linutronix.de>
  24 Link: http://lkml.kernel.org/r/5601c15ea9b3113d288953fd2838b18bedf6bc67.1509794321.git.luto@kernel.org
  25 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  26 (cherry picked from commit fec8f5ae1715a01c72ad52cb2ecd8aacaf142302)
  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 a1cdabf77d7ed9ba02697ad8beb04adf46a7c7b8)
  30 Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
  31 ---
  32  tools/testing/selftests/x86/ldt_gdt.c | 17 ++++++++++++++++-
  33  1 file changed, 16 insertions(+), 1 deletion(-)
  34
  35 diff --git a/tools/testing/selftests/x86/ldt_gdt.c b/tools/testing/selftests/x86/ldt_gdt.c
  36 index 05d0d6f49c2c..8e290c9b2c3f 100644
  37 --- a/tools/testing/selftests/x86/ldt_gdt.c
  38 +++ b/tools/testing/selftests/x86/ldt_gdt.c
  39 @@ -403,9 +403,24 @@ static void do_simple_tests(void)
  40         install_invalid(&desc, false);
  41
  42         desc.seg_not_present = 0;
  43 -       desc.read_exec_only = 0;
  44         desc.seg_32bit = 1;
  45 +       desc.read_exec_only = 0;
  46 +       desc.limit = 0xfffff;
  47 +
  48         install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S | AR_P | AR_DB);
  49 +
  50 +       desc.limit_in_pages = 1;
  51 +
  52 +       install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S | AR_P | AR_DB | AR_G);
  53 +       desc.read_exec_only = 1;
  54 +       install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA | AR_S | AR_P | AR_DB | AR_G);
  55 +       desc.contents = 1;
  56 +       desc.read_exec_only = 0;
  57 +       install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA_EXPDOWN | AR_S | AR_P | AR_DB | AR_G);
  58 +       desc.read_exec_only = 1;
  59 +       install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA_EXPDOWN | AR_S | AR_P | AR_DB | AR_G);
  60 +
  61 +       desc.limit = 0;
  62         install_invalid(&desc, true);
  63  }
  64
  65 --
  66 2.14.2
  67