On Thu, Oct 19, 2023 at 10:52 AM Mateusz Guzik <[email protected]> wrote:
> On 10/19/23, Paul Moore <[email protected]> wrote:
> > Thinking about it a bit more this morning, I think we can safely
> > ignore the non-@current case in audit_exe_compare() as the whole point
> > of the audit exe filter is to record the actions of processes
> > instantiated from that executable file; if the @current task is not
> > being logged/filtered, we shouldn't have to worry about the exe
> > filter.
>
> I did a quick stab at figuring out whether one can get there with
> non-current to begin with, but did not convince myself it is not
> possible.
>
> That said, should you repost, I think refing and unrefing mm should be a
> voided.
We have to deref current->mm to get the exe_file, but so long as we
get a reference with mmget()/mmput() it should be safe, no?
> The bug showed up with 18c91bb2d87268d23868bf13508f5bc9cf04e89a
> ("prlimit: do not grab the tasklist_lock") which converted that lock
> to task_lock. So I don't think pointing at my patch as "Fixes" is
> accurate, but I'm not going to insist. ;)
Hmm, 18c91bb2d872 doesn't look like it adds a call to task_lock(), did
you copy-n-past the wrong commit or am I missing something? From what
I can see, the task_lock() was first introduced back in 2009 with
86f162f4c75c ("rlimits: do security check under task_lock").
--
paul-moore.com
