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[PATCH 2/2] x86/mm/KASLR: Correct the upper boundary of KALSR mm regions if adjacent to EFI

Started byBaoquan He <bhe@redhat.com>
First post2017-03-08 08:50 +0100
Last post2017-03-08 16:50 +0100
Articles 4 — 4 participants

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  [PATCH 2/2] x86/mm/KASLR: Correct the upper boundary of KALSR mm regions if adjacent to EFI Baoquan He <bhe@redhat.com> - 2017-03-08 08:50 +0100
    Re: [PATCH 2/2] x86/mm/KASLR: Correct the upper boundary of KALSR mm  regions if adjacent to EFI Dave Young <dyoung@redhat.com> - 2017-03-08 09:30 +0100
      Re: [PATCH 2/2] x86/mm/KASLR: Correct the upper boundary of KALSR mm  regions if adjacent to EFI Bhupesh Sharma <bhsharma@redhat.com> - 2017-03-08 09:40 +0100
        Re: [PATCH 2/2] x86/mm/KASLR: Correct the upper boundary of KALSR mm  regions if adjacent to EFI Thomas Garnier <thgarnie@google.com> - 2017-03-08 16:50 +0100

#1594913 — [PATCH 2/2] x86/mm/KASLR: Correct the upper boundary of KALSR mm regions if adjacent to EFI

FromBaoquan He <bhe@redhat.com>
Date2017-03-08 08:50 +0100
Subject[PATCH 2/2] x86/mm/KASLR: Correct the upper boundary of KALSR mm regions if adjacent to EFI
Message-ID<tiEw9-3fU-11@gated-at.bofh.it>
EFI allocates runtime services regions top-down, starting from EFI_VA_START
to EFI_VA_END. So EFI_VA_START is bigger than EFI_VA_END and is the end of
EFI region. The upper boundary of memory regions randomized by KASLR should
be EFI_VA_END if it's adjacent to EFI region, but not EFI_VA_START.

Correct it in this patch.

Signed-off-by: Baoquan He <bhe@redhat.com>
---
 arch/x86/mm/kaslr.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c
index 887e571..aed2064 100644
--- a/arch/x86/mm/kaslr.c
+++ b/arch/x86/mm/kaslr.c
@@ -48,7 +48,7 @@ static const unsigned long vaddr_start = __PAGE_OFFSET_BASE;
 #if defined(CONFIG_X86_ESPFIX64)
 static const unsigned long vaddr_end = ESPFIX_BASE_ADDR;
 #elif defined(CONFIG_EFI)
-static const unsigned long vaddr_end = EFI_VA_START;
+static const unsigned long vaddr_end = EFI_VA_END;
 #else
 static const unsigned long vaddr_end = __START_KERNEL_map;
 #endif
@@ -105,7 +105,7 @@ void __init kernel_randomize_memory(void)
 	 */
 	BUILD_BUG_ON(vaddr_start >= vaddr_end);
 	BUILD_BUG_ON(IS_ENABLED(CONFIG_X86_ESPFIX64) &&
-		     vaddr_end >= EFI_VA_START);
+		     vaddr_end >= EFI_VA_END);
 	BUILD_BUG_ON((IS_ENABLED(CONFIG_X86_ESPFIX64) ||
 		      IS_ENABLED(CONFIG_EFI)) &&
 		     vaddr_end >= __START_KERNEL_map);
-- 
2.5.5

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#1594930 — Re: [PATCH 2/2] x86/mm/KASLR: Correct the upper boundary of KALSR mm regions if adjacent to EFI

FromDave Young <dyoung@redhat.com>
Date2017-03-08 09:30 +0100
SubjectRe: [PATCH 2/2] x86/mm/KASLR: Correct the upper boundary of KALSR mm regions if adjacent to EFI
Message-ID<tiF8S-3JU-11@gated-at.bofh.it>
In reply to#1594913
On 03/08/17 at 03:47pm, Baoquan He wrote:
> EFI allocates runtime services regions top-down, starting from EFI_VA_START
> to EFI_VA_END. So EFI_VA_START is bigger than EFI_VA_END and is the end of
> EFI region. The upper boundary of memory regions randomized by KASLR should
> be EFI_VA_END if it's adjacent to EFI region, but not EFI_VA_START.
> 
> Correct it in this patch.
> 
> Signed-off-by: Baoquan He <bhe@redhat.com>
> ---
>  arch/x86/mm/kaslr.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c
> index 887e571..aed2064 100644
> --- a/arch/x86/mm/kaslr.c
> +++ b/arch/x86/mm/kaslr.c
> @@ -48,7 +48,7 @@ static const unsigned long vaddr_start = __PAGE_OFFSET_BASE;
>  #if defined(CONFIG_X86_ESPFIX64)
>  static const unsigned long vaddr_end = ESPFIX_BASE_ADDR;
>  #elif defined(CONFIG_EFI)
> -static const unsigned long vaddr_end = EFI_VA_START;
> +static const unsigned long vaddr_end = EFI_VA_END;
>  #else
>  static const unsigned long vaddr_end = __START_KERNEL_map;
>  #endif
> @@ -105,7 +105,7 @@ void __init kernel_randomize_memory(void)
>  	 */
>  	BUILD_BUG_ON(vaddr_start >= vaddr_end);
>  	BUILD_BUG_ON(IS_ENABLED(CONFIG_X86_ESPFIX64) &&
> -		     vaddr_end >= EFI_VA_START);
> +		     vaddr_end >= EFI_VA_END);
>  	BUILD_BUG_ON((IS_ENABLED(CONFIG_X86_ESPFIX64) ||
>  		      IS_ENABLED(CONFIG_EFI)) &&
>  		     vaddr_end >= __START_KERNEL_map);
> -- 
> 2.5.5
> 

Acked-by: Dave Young <dyoung@redhat.com>

Thanks
Dave

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#1594940 — Re: [PATCH 2/2] x86/mm/KASLR: Correct the upper boundary of KALSR mm regions if adjacent to EFI

FromBhupesh Sharma <bhsharma@redhat.com>
Date2017-03-08 09:40 +0100
SubjectRe: [PATCH 2/2] x86/mm/KASLR: Correct the upper boundary of KALSR mm regions if adjacent to EFI
Message-ID<tiFix-3NE-1@gated-at.bofh.it>
In reply to#1594930
On Wed, Mar 8, 2017 at 1:48 PM, Dave Young <dyoung@redhat.com> wrote:
> On 03/08/17 at 03:47pm, Baoquan He wrote:
>> EFI allocates runtime services regions top-down, starting from EFI_VA_START
>> to EFI_VA_END. So EFI_VA_START is bigger than EFI_VA_END and is the end of
>> EFI region. The upper boundary of memory regions randomized by KASLR should
>> be EFI_VA_END if it's adjacent to EFI region, but not EFI_VA_START.
>>
>> Correct it in this patch.
>>
>> Signed-off-by: Baoquan He <bhe@redhat.com>
>> ---
>>  arch/x86/mm/kaslr.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c
>> index 887e571..aed2064 100644
>> --- a/arch/x86/mm/kaslr.c
>> +++ b/arch/x86/mm/kaslr.c
>> @@ -48,7 +48,7 @@ static const unsigned long vaddr_start = __PAGE_OFFSET_BASE;
>>  #if defined(CONFIG_X86_ESPFIX64)
>>  static const unsigned long vaddr_end = ESPFIX_BASE_ADDR;
>>  #elif defined(CONFIG_EFI)
>> -static const unsigned long vaddr_end = EFI_VA_START;
>> +static const unsigned long vaddr_end = EFI_VA_END;
>>  #else
>>  static const unsigned long vaddr_end = __START_KERNEL_map;
>>  #endif
>> @@ -105,7 +105,7 @@ void __init kernel_randomize_memory(void)
>>        */
>>       BUILD_BUG_ON(vaddr_start >= vaddr_end);
>>       BUILD_BUG_ON(IS_ENABLED(CONFIG_X86_ESPFIX64) &&
>> -                  vaddr_end >= EFI_VA_START);
>> +                  vaddr_end >= EFI_VA_END);
>>       BUILD_BUG_ON((IS_ENABLED(CONFIG_X86_ESPFIX64) ||
>>                     IS_ENABLED(CONFIG_EFI)) &&
>>                    vaddr_end >= __START_KERNEL_map);
>> --
>> 2.5.5
>>
>
> Acked-by: Dave Young <dyoung@redhat.com>
>

Thanks Bao for this fix. This makes the KASLR code consistent with
Address space markers hints in [1]

[1] http://lxr.free-electrons.com/source/arch/x86/mm/dump_pagetables.c#L82

Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com>

Regards,
Bhupesh

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#1595303 — Re: [PATCH 2/2] x86/mm/KASLR: Correct the upper boundary of KALSR mm regions if adjacent to EFI

FromThomas Garnier <thgarnie@google.com>
Date2017-03-08 16:50 +0100
SubjectRe: [PATCH 2/2] x86/mm/KASLR: Correct the upper boundary of KALSR mm regions if adjacent to EFI
Message-ID<tiM0G-86-21@gated-at.bofh.it>
In reply to#1594940
Thanks for the change.

Acked-by: Thomas Garnier <thgarnie@google.com>

On Wed, Mar 8, 2017 at 12:35 AM, Bhupesh Sharma <bhsharma@redhat.com> wrote:
> On Wed, Mar 8, 2017 at 1:48 PM, Dave Young <dyoung@redhat.com> wrote:
>> On 03/08/17 at 03:47pm, Baoquan He wrote:
>>> EFI allocates runtime services regions top-down, starting from EFI_VA_START
>>> to EFI_VA_END. So EFI_VA_START is bigger than EFI_VA_END and is the end of
>>> EFI region. The upper boundary of memory regions randomized by KASLR should
>>> be EFI_VA_END if it's adjacent to EFI region, but not EFI_VA_START.
>>>
>>> Correct it in this patch.
>>>
>>> Signed-off-by: Baoquan He <bhe@redhat.com>
>>> ---
>>>  arch/x86/mm/kaslr.c | 4 ++--
>>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c
>>> index 887e571..aed2064 100644
>>> --- a/arch/x86/mm/kaslr.c
>>> +++ b/arch/x86/mm/kaslr.c
>>> @@ -48,7 +48,7 @@ static const unsigned long vaddr_start = __PAGE_OFFSET_BASE;
>>>  #if defined(CONFIG_X86_ESPFIX64)
>>>  static const unsigned long vaddr_end = ESPFIX_BASE_ADDR;
>>>  #elif defined(CONFIG_EFI)
>>> -static const unsigned long vaddr_end = EFI_VA_START;
>>> +static const unsigned long vaddr_end = EFI_VA_END;
>>>  #else
>>>  static const unsigned long vaddr_end = __START_KERNEL_map;
>>>  #endif
>>> @@ -105,7 +105,7 @@ void __init kernel_randomize_memory(void)
>>>        */
>>>       BUILD_BUG_ON(vaddr_start >= vaddr_end);
>>>       BUILD_BUG_ON(IS_ENABLED(CONFIG_X86_ESPFIX64) &&
>>> -                  vaddr_end >= EFI_VA_START);
>>> +                  vaddr_end >= EFI_VA_END);
>>>       BUILD_BUG_ON((IS_ENABLED(CONFIG_X86_ESPFIX64) ||
>>>                     IS_ENABLED(CONFIG_EFI)) &&
>>>                    vaddr_end >= __START_KERNEL_map);
>>> --
>>> 2.5.5
>>>
>>
>> Acked-by: Dave Young <dyoung@redhat.com>
>>
>
> Thanks Bao for this fix. This makes the KASLR code consistent with
> Address space markers hints in [1]
>
> [1] http://lxr.free-electrons.com/source/arch/x86/mm/dump_pagetables.c#L82
>
> Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com>
>
> Regards,
> Bhupesh



-- 
Thomas

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