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

   1 From 0000000000000000000000000000000000000000 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] selftests/x86/ldt_get: Add a few additional tests for limits
   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 We weren't testing the .limit and .limit_in_pages fields very well.
  12 Add more tests.
  13
  14 This addition seems to trigger the "bits 16:19 are undefined" issue
  15 that was fixed in an earlier patch.  I think that, at least on my
  16 CPU, the high nibble of the limit ends in LAR bits 16:19.
  17
  18 Signed-off-by: Andy Lutomirski <luto@kernel.org>
  19 Cc: Borislav Petkov <bpetkov@suse.de>
  20 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  21 Cc: Peter Zijlstra <peterz@infradead.org>
  22 Cc: Thomas Gleixner <tglx@linutronix.de>
  23 Link: http://lkml.kernel.org/r/5601c15ea9b3113d288953fd2838b18bedf6bc67.1509794321.git.luto@kernel.org
  24 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  25 (cherry picked from commit fec8f5ae1715a01c72ad52cb2ecd8aacaf142302)
  26 Signed-off-by: Andy Whitcroft <apw@canonical.com>
  27 Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
  28 (cherry picked from commit a1cdabf77d7ed9ba02697ad8beb04adf46a7c7b8)
  29 Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
  30 ---
  31  tools/testing/selftests/x86/ldt_gdt.c | 17 ++++++++++++++++-
  32  1 file changed, 16 insertions(+), 1 deletion(-)
  33
  34 diff --git a/tools/testing/selftests/x86/ldt_gdt.c b/tools/testing/selftests/x86/ldt_gdt.c
  35 index 05d0d6f49c2c..8e290c9b2c3f 100644
  36 --- a/tools/testing/selftests/x86/ldt_gdt.c
  37 +++ b/tools/testing/selftests/x86/ldt_gdt.c
  38 @@ -403,9 +403,24 @@ static void do_simple_tests(void)
  39         install_invalid(&desc, false);
  40
  41         desc.seg_not_present = 0;
  42 -       desc.read_exec_only = 0;
  43         desc.seg_32bit = 1;
  44 +       desc.read_exec_only = 0;
  45 +       desc.limit = 0xfffff;
  46 +
  47         install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S | AR_P | AR_DB);
  48 +
  49 +       desc.limit_in_pages = 1;
  50 +
  51 +       install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S | AR_P | AR_DB | AR_G);
  52 +       desc.read_exec_only = 1;
  53 +       install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA | AR_S | AR_P | AR_DB | AR_G);
  54 +       desc.contents = 1;
  55 +       desc.read_exec_only = 0;
  56 +       install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA_EXPDOWN | AR_S | AR_P | AR_DB | AR_G);
  57 +       desc.read_exec_only = 1;
  58 +       install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA_EXPDOWN | AR_S | AR_P | AR_DB | AR_G);
  59 +
  60 +       desc.limit = 0;
  61         install_invalid(&desc, true);
  62  }
  63
  64 --
  65 2.14.2
  66