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Groups > linux.kernel > #1277857
| From | Eric Dumazet <eric.dumazet@gmail.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: use-after-free in sock_wake_async |
| Date | 2015-11-25 23:50 +0100 |
| Message-ID | <qyR2W-3ZJ-9@gated-at.bofh.it> (permalink) |
| References | (13 earlier) <qyOor-2en-25@gated-at.bofh.it> <qyORs-2F7-29@gated-at.bofh.it> <qyPku-2Rv-7@gated-at.bofh.it> <qyQqf-3L8-31@gated-at.bofh.it> <qyQTg-3Vd-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Wed, 2015-11-25 at 23:32 +0100, Hannes Frederic Sowa wrote:
> On Wed, Nov 25, 2015, at 23:09, Eric Dumazet wrote:
> > On Wed, 2015-11-25 at 20:57 +0000, Rainer Weikusat wrote:
> >
> > > I do agree that keeping the ->sk_data_ready outside of the lock will
> > > very likely have performance advantages. That's just something I
> > > wouldn't have undertaken because I'd be reluctant to make a fairly
> > > complicated change to a lot of code.
> >
> > All I am saying is that we can keep current performance.
> >
> > We already have the core infrastructure, we only need to properly use
> > it.
> >
> > I will split my changes in two parts.
> >
> > One part doing a very boring change of
> >
> > rename SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA
> > for X in SOCK_ASYNC_NOSPACE SOCK_ASYNC_WAITDATA
> >
> > set_bit(X, &sk->sk_socket->flags) -> sk_set_bit(X, sk)
> > clear_bit(X, &sk->sk_socket->flags) -> sk_clear_bit(X, sk)
>
> sk_set_bit and sk_clear_bit will forward the set_bit and clear_bit into
> the socket_wq like you explained above?
In the first patch (no functional change), the helpers will look like
static void inline sk_set_bit(int nr, struct sock *sk)
{
set_bit(nr, &sk->sk_socket->flags);
}
Then the second patch will change the helper to :
static void inline sk_set_bit(int nr, struct sock *sk)
{
set_bit(nr, &sk->sk_wq_raw->flags);
}
>
> > The rename will help backports to catch code that might have been
> > removed in recent kernels.
> >
> > Then the second patch will do the actual changes, and they will look
> > very sensible for people wanting to review them, and or familiar with
> > the stack, do not worry ;)
>
> Do you see a chance to inline socket_wq into struct socket and discard
> struct socket_alloc in one go by rcu in socket_destroy_inode?
???
I guess you missed the whole point to have socket_wq allocated outside
of the inode :(
inodes are not rcu protected (yet). I certainly don't want to mess with
VFS, we have enough problems in net/ directory already.
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use-after-free in sock_wake_async Dmitry Vyukov <dvyukov@google.com> - 2015-11-24 15:20 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <edumazet@google.com> - 2015-11-24 16:30 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <eric.dumazet@gmail.com> - 2015-11-24 16:40 +0100
Re: use-after-free in sock_wake_async Jason Baron <jbaron@akamai.com> - 2015-11-24 22:40 +0100
Re: use-after-free in sock_wake_async Benjamin LaHaise <bcrl@kvack.org> - 2015-11-24 22:50 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <edumazet@google.com> - 2015-11-24 23:10 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <edumazet@google.com> - 2015-11-24 23:20 +0100
Re: use-after-free in sock_wake_async Al Viro <viro@ZenIV.linux.org.uk> - 2015-11-24 22:50 +0100
Re: use-after-free in sock_wake_async Rainer Weikusat <rweikusat@mobileactivedefense.com> - 2015-11-25 00:40 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <edumazet@google.com> - 2015-11-25 00:50 +0100
Re: use-after-free in sock_wake_async Rainer Weikusat <rweikusat@mobileactivedefense.com> - 2015-11-25 02:20 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <edumazet@google.com> - 2015-11-25 02:20 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <eric.dumazet@gmail.com> - 2015-11-25 03:30 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <eric.dumazet@gmail.com> - 2015-11-25 06:50 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <eric.dumazet@gmail.com> - 2015-11-25 15:20 +0100
Re: use-after-free in sock_wake_async Rainer Weikusat <rweikusat@mobileactivedefense.com> - 2015-11-25 17:50 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <eric.dumazet@gmail.com> - 2015-11-25 18:20 +0100
Re: use-after-free in sock_wake_async Rainer Weikusat <rweikusat@mobileactivedefense.com> - 2015-11-25 18:40 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <eric.dumazet@gmail.com> - 2015-11-25 19:00 +0100
Re: use-after-free in sock_wake_async Rainer Weikusat <rweikusat@mobileactivedefense.com> - 2015-11-25 19:30 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <eric.dumazet@gmail.com> - 2015-11-25 19:40 +0100
Re: use-after-free in sock_wake_async Rainer Weikusat <rweikusat@mobileactivedefense.com> - 2015-11-25 20:40 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <eric.dumazet@gmail.com> - 2015-11-25 21:00 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <eric.dumazet@gmail.com> - 2015-11-25 21:30 +0100
Re: use-after-free in sock_wake_async Rainer Weikusat <rweikusat@mobileactivedefense.com> - 2015-11-25 22:00 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <eric.dumazet@gmail.com> - 2015-11-25 23:10 +0100
Re: use-after-free in sock_wake_async Hannes Frederic Sowa <hannes@stressinduktion.org> - 2015-11-25 23:40 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <eric.dumazet@gmail.com> - 2015-11-25 23:50 +0100
Re: use-after-free in sock_wake_async Hannes Frederic Sowa <hannes@stressinduktion.org> - 2015-11-26 00:00 +0100
Re: use-after-free in sock_wake_async Hannes Frederic Sowa <hannes@stressinduktion.org> - 2015-11-26 14:40 +0100
Re: use-after-free in sock_wake_async Hannes Frederic Sowa <hannes@stressinduktion.org> - 2015-11-26 15:40 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <eric.dumazet@gmail.com> - 2015-11-26 17:00 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <eric.dumazet@gmail.com> - 2015-11-26 18:10 +0100
Re: use-after-free in sock_wake_async Hannes Frederic Sowa <hannes@stressinduktion.org> - 2015-11-26 18:20 +0100
Re: use-after-free in sock_wake_async Hannes Frederic Sowa <hannes@stressinduktion.org> - 2015-11-26 18:10 +0100
Re: use-after-free in sock_wake_async Eric Dumazet <eric.dumazet@gmail.com> - 2015-11-26 18:30 +0100
Re: use-after-free in sock_wake_async Rainer Weikusat <rweikusat@mobileactivedefense.com> - 2015-11-25 02:20 +0100
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