modules size in mkimage

modules size in mkimage

[Andrei Borzenkov]

mkimage sets module size to aligned value; later it is used to actually 
process it which /may/ lead to inconsistency (as any comparison is 
against stored aligned size, not actual module size).

Same applies to all other embedded types actually. The only one that 
does it right is pubkey.

Just to make sure I do not miss something obvious; otherwise I'll make a 
patch.

Re: modules size in mkimage

[Vladimir 'phcoder' Serbinenko]

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Le 31 oct. 2015 8:02 AM, "Andrei Borzenkov" <arvidjaar@gmail.com> a écrit :
>
> mkimage sets module size to aligned value; later it is used to actually
process it which /may/ lead to inconsistency (as any comparison is against
stored aligned size, not actual module size).
>
Which inconsistency do you have in mind?
> Same applies to all other embedded types actually. The only one that does
it right is pubkey.
>
> Just to make sure I do not miss something obvious; otherwise I'll make a
patch.
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> https://lists.gnu.org/mailman/listinfo/grub-devel

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Re: modules size in mkimage

[Andrei Borzenkov]

04.11.2015 14:21, Vladimir 'phcoder' Serbinenko пишет:
> Le 31 oct. 2015 8:02 AM, "Andrei Borzenkov" <arvidjaar@gmail.com> a écrit :
>>
>> mkimage sets module size to aligned value; later it is used to actually
> process it which /may/ lead to inconsistency (as any comparison is against
> stored aligned size, not actual module size).
>>
> Which inconsistency do you have in mind?

   if (size < e->e_shoff + e->e_shentsize * e->e_shnum)
     {
       grub_error (GRUB_ERR_BAD_OS, "ELF sections outside core");

Re: modules size in mkimage

[Vladimir 'phcoder' Serbinenko]

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Le 4 nov. 2015 12:26 PM, "Andrei Borzenkov" <arvidjaar@gmail.com> a écrit :
>
> 04.11.2015 14:21, Vladimir 'phcoder' Serbinenko пишет:
>
>> Le 31 oct. 2015 8:02 AM, "Andrei Borzenkov" <arvidjaar@gmail.com> a
écrit :
>>>
>>>
>>> mkimage sets module size to aligned value; later it is used to actually
>>
>> process it which /may/ lead to inconsistency (as any comparison is
against
>> stored aligned size, not actual module size).
>>>
>>>
>> Which inconsistency do you have in mind?
>
>
>   if (size < e->e_shoff + e->e_shentsize * e->e_shnum)
>     {
>       grub_error (GRUB_ERR_BAD_OS, "ELF sections outside core");
>
This is just to avoid accessing unallocated data. In this case the memory
is allocated. So it's a minor issue. I'm more concerned with some module
iterator breaking
>
>
>
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> https://lists.gnu.org/mailman/listinfo/grub-devel

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