Re: [PATCH AUTOSEL 6.6 054/139] net: tls: wait for async completion on last message

[Sasha Levin]

On Wed, Oct 02, 2024 at 05:50:25AM -0700, Jakub Kicinski wrote:
> On Wed, 25 Sep 2024 08:07:54 -0400 Sasha Levin wrote:
> > From: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> >
> > [ Upstream commit 54001d0f2fdbc7852136a00f3e6fc395a9547ae5 ]
> >
> > When asynchronous encryption is used KTLS sends out the final data at
> > proto->close time. This becomes problematic when the task calling
> > close() receives a signal. In this case it can happen that
> > tcp_sendmsg_locked() called at close time returns -ERESTARTSYS and the
> > final data is not sent.
> >
> > The described situation happens when KTLS is used in conjunction with
> > io_uring, as io_uring uses task_work_add() to add work to the current
> > userspace task. A discussion of the problem along with a reproducer can
> > be found in [1] and [2]
> >
> > Fix this by waiting for the asynchronous encryption to be completed on
> > the final message. With this there is no data left to be sent at close
> > time.
>
> I wouldn't backport this, it may cause perf regressions.

Dropped, thanks!

--
Thanks,
Sasha