netdev - Re: [PATCH v2 net-next 1/2] tcp: fix over estimation in sk_forced_mem

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAEA6p_A91+jnVSx3tiKQiq38bXM-0GOBx4auQMA=xPRTbcp3VA@mail.gmail.com>
Date:   Tue, 14 Jun 2022 11:39:13 -0700
From:   Wei Wang <weiwan@...gle.com>
To:     Soheil Hassas Yeganeh <soheil@...gle.com>
Cc:     Eric Dumazet <eric.dumazet@...il.com>,
        "David S . Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>,
        netdev <netdev@...r.kernel.org>,
        Shakeel Butt <shakeelb@...gle.com>,
        Neal Cardwell <ncardwell@...gle.com>,
        Eric Dumazet <edumazet@...gle.com>
Subject: Re: [PATCH v2 net-next 1/2] tcp: fix over estimation in sk_forced_mem_schedule()

On Tue, Jun 14, 2022 at 10:41 AM Soheil Hassas Yeganeh
<soheil@...gle.com> wrote:
>
> On Tue, Jun 14, 2022 at 1:17 PM Eric Dumazet <eric.dumazet@...il.com> wrote:
> >
> > From: Eric Dumazet <edumazet@...gle.com>
> >
> > sk_forced_mem_schedule() has a bug similar to ones fixed
> > in commit 7c80b038d23e ("net: fix sk_wmem_schedule() and
> > sk_rmem_schedule() errors")
> >
> > While this bug has little chance to trigger in old kernels,
> > we need to fix it before the following patch.
> >
> > Fixes: d83769a580f1 ("tcp: fix possible deadlock in tcp_send_fin()")
> > Signed-off-by: Eric Dumazet <edumazet@...gle.com>

Reviewed-by: Wei Wang <weiwan@...gle.com>

>
> Acked-by: Soheil Hassas Yeganeh <soheil@...gle.com>
>
> > ---
> >  net/ipv4/tcp_output.c | 7 ++++---
> >  1 file changed, 4 insertions(+), 3 deletions(-)
> >
> > diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
> > index 8ab98e1aca6797a51eaaf8886680d2001a616948..18c913a2347a984ae8cf2793bb8991e59e5e94ab 100644
> > --- a/net/ipv4/tcp_output.c
> > +++ b/net/ipv4/tcp_output.c
> > @@ -3362,11 +3362,12 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
> >   */
> >  void sk_forced_mem_schedule(struct sock *sk, int size)
> >  {
> > -       int amt;
> > +       int delta, amt;
> >
> > -       if (size <= sk->sk_forward_alloc)
> > +       delta = size - sk->sk_forward_alloc;
> > +       if (delta <= 0)
> >                 return;
> > -       amt = sk_mem_pages(size);
> > +       amt = sk_mem_pages(delta);
> >         sk->sk_forward_alloc += amt << PAGE_SHIFT;
> >         sk_memory_allocated_add(sk, amt);
> >
> > --
> > 2.36.1.476.g0c4daa206d-goog
> >