V4 [PATCH] x86/CET: Fix property note parser [BZ #23467]

[H.J. Lu]

On Mon, Jul 30, 2018 at 12:43 PM, Carlos O'Donell <carlos@redhat.com> wrote:
> On 07/30/2018 03:34 PM, H.J. Lu wrote:
>> On Mon, Jul 30, 2018 at 12:09 PM, Adhemerval Zanella
>> <adhemerval.zanella@linaro.org> wrote:
>>>
>>> On 30/07/2018 15:56, H.J. Lu wrote:
>>>>>> +
>>>>>> +  test (bar);
>>>>>> +
>>>>>> +  return EXIT_FAILURE;
>>>>>> +}
>>>>>> diff --git a/sysdeps/x86/dl-prop.h b/sysdeps/x86/dl-prop.h
>>>>>> index 35d3f16a23..d9e0770e29 100644
>>>>>> --- a/sysdeps/x86/dl-prop.h
>>>>>> +++ b/sysdeps/x86/dl-prop.h
>>>>>> @@ -73,7 +73,7 @@ _dl_process_cet_property_note (struct link_map *l,
>>>>>>         unsigned char *ptr = (unsigned char *) (note + 1) + 4;
>>>>>>         unsigned char *ptr_end = ptr + note->n_descsz;
>>>>>>
>>>>> Should we care for overflow here (I guess not since we don't really
>>>>> protected against ill-formed elf files in general)?
>>>> We do protect against ill-formed notes.  When we get here, the whole
>>>> note has been loaded into memory.   There won't be overflow.
>>> Indeed, LGTM to me then.
>> This is the updated patch I am going to check in today.
>
> Please get final Reviewed-by from the release manager for any patches
> which are materially different from those reviewed.
>
>> From bed8cb21b6bd67bed148713259779a8a3e3f844d Mon Sep 17 00:00:00 2001
>> From: "H.J. Lu" <hjl.tools@gmail.com>
>> Date: Fri, 27 Jul 2018 20:34:55 -0700
>> Subject: [PATCH] x86/CET: Fix property note parser [BZ #23467]
>>
>> GNU_PROPERTY_X86_FEATURE_1_AND may not be the first property item.  We
>> need to check each property item until we reach the end of the property
>> or find GNU_PROPERTY_X86_FEATURE_1_AND.
>>
>> This patch adds 2 tests.  The first test checks if IBT is enabled and
>> the second test reads the output from the first test to check if IBT
>> is is enabled.  The second second test fails if IBT isn't enabled
>> properly.
>>
>>       [BZ #23467]
>>       * sysdeps/unix/sysv/linux/x86/Makefile (tests): Add
>>       tst-cet-property-1 and tst-cet-property-2 if CET is enabled.
>>       (CFLAGS-tst-cet-property-1.o): New.
>>       (ASFLAGS-tst-cet-property-dep-2.o): Likewise.
>>       ($(objpfx)tst-cet-property-2): Likewise.
>>       ($(objpfx)tst-cet-property-2.out): Likewise.
>>       * sysdeps/unix/sysv/linux/x86/tst-cet-property-1.c: New file.
>>       * sysdeps/unix/sysv/linux/x86/tst-cet-property-2.c: Likewise.
>>       * sysdeps/unix/sysv/linux/x86/tst-cet-property-dep-2.S: Likewise.
>>       * sysdeps/x86/dl-prop.h (_dl_process_cet_property_note): Parse
>>       each property item until GNU_PROPERTY_X86_FEATURE_1_AND is
>>       found.
>> ---
>>  sysdeps/unix/sysv/linux/x86/Makefile          | 15 +++++
>>  .../unix/sysv/linux/x86/tst-cet-property-1.c  | 40 +++++++++++++
>>  .../unix/sysv/linux/x86/tst-cet-property-2.c  | 58 ++++++++++++++++++
>>  .../sysv/linux/x86/tst-cet-property-dep-2.S   | 60 +++++++++++++++++++
>>  sysdeps/x86/dl-prop.h                         | 24 +++++---
>>  5 files changed, 188 insertions(+), 9 deletions(-)
>>  create mode 100644 sysdeps/unix/sysv/linux/x86/tst-cet-property-1.c
>>  create mode 100644 sysdeps/unix/sysv/linux/x86/tst-cet-property-2.c
>>  create mode 100644 sysdeps/unix/sysv/linux/x86/tst-cet-property-dep-2.S
>
> OK for 2.28 with 5 comment additions.
>
> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
>

This is the updated patch I am checking in.

Thanks.

-- 
H.J.
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