Re: [PATCH 15/19] kernel: convert audit_tree.count from atomic_t to refcount_t

[Kees Cook]

On Tue, Feb 28, 2017 at 2:11 PM, Paul Moore <paul@xxxxxxxxxxxxxx> wrote:
> On Tue, Feb 21, 2017 at 2:15 AM, Reshetova, Elena
> <elena.reshetova@xxxxxxxxx> wrote:
>>> On Mon, Feb 20, 2017 at 5:19 AM, Elena Reshetova
>>> <elena.reshetova@xxxxxxxxx> wrote:
>>> > refcount_t type and corresponding API should be
>>> > used instead of atomic_t when the variable is used as
>>> > a reference counter. This allows to avoid accidental
>>> > refcounter overflows that might lead to use-after-free
>>> > situations.
>>> >
>>> > Signed-off-by: Elena Reshetova <elena.reshetova@xxxxxxxxx>
>>> > Signed-off-by: Hans Liljestrand <ishkamiel@xxxxxxxxx>
>>> > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
>>> > Signed-off-by: David Windsor <dwindsor@xxxxxxxxx>
>>> > ---
>>> >  kernel/audit_tree.c | 8 ++++----
>>> >  1 file changed, 4 insertions(+), 4 deletions(-)
>>>
>>> No objection on my end, same for patch 16/19.
>>>
>>> I have no problem merging both these patches into the audit/next
>>> branch after the merge window, is that your goal or are you merging
>>> these via a different tree?
>>
>> Thank you Paul! I think it is better if they go through the trees they supposed to go through
>> since this way they would get more testing and etc. So, please take the relevant ones to your tree when the time is right.
>>
>> After the first round, I guess we will see what patches are not propagating and then maybe take them via Kees tree.
>
> I just realized that include/linux/refcount.h didn't make it into
> v4.10 which means there is going to be delay until I merge them into
> the audit tree (I don't base the tree on -rc releases except under
> extreme circumstances).  I've got the patches queued up in a private
> holding branch (I added #includes BTW) so I won't forget, but as a
> FYI, they likely won't make it in until v4.12.

I'm not asking for you to change this, but I am curious: doesn't that
force you to always be a release behind? I've tended to base trees on
-rc2 (and then the final release while the next merge window is open).
But that may be because I tend to have such wide dependencies...

-Kees

-- 
Kees Cook
Pixel Security