ACK/cmnt: [SRU][Trusty][PATCH 0/2] Fix for CVE-2017-12190

[Kleber Souza]

On 12/12/17 11:01, Stefan Bader wrote:
> On 08.12.2017 13:37, Kleber Sacilotto de Souza wrote:
>> Patch 1/2 is a simple backport to adjust for the file name and context.
>>
>> Patch 2/2 needed backport to adjust for context, and because Xenial kernel is
>> still using page_cache_release() instead of put_page().
> 
> You men Trusty kernel, right? I take it that put_page and page_cache_release end
> up being the same thing? Otherwise maybe the two put_page calls added should
> have been page_cache_release instead. If its the same it does not matter really.

Hi Stefan,

Yes, I meant Trusty here but it's the same case as for the Xenial kernel.

page_cache_release() is defined as:

include/linux/pagemap.h:
#define page_cache_release(page)        put_page(page)

Later commit 09cbfeaf1a5a (mm, fs: get rid of PAGE_CACHE_* and
page_cache_{get,release} macros) got rid of this definition, along with
other useless ones.

> 
> For that case ...
>>
>> https://people.canonical.com/~ubuntu-security/cve/2017/CVE-2017-12190.html
>>
>> Al Viro (1):
>>   more bio_map_user_iov() leak fixes
>>
>> Vitaly Mayatskikh (1):
>>   fix unbalanced page refcounting in bio_map_user_iov
>>
>>  fs/bio.c | 22 +++++++++++++++++-----
>>  1 file changed, 17 insertions(+), 5 deletions(-)
>>
> Acked-by: Stefan Bader <stefan.bader at canonical.com>
> 
> 
> 
>