From: Christoph Hellwig <hch@lst.de>
To: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>,
netdev@vger.kernel.org, Neil Horman <nhorman@tuxdriver.com>,
linux-sctp@vger.kernel.org
Subject: Re: [PATCH net-next] sctp: fix slab-out-of-bounds in SCTP_DELAYED_SACK processing
Date: Fri, 24 Jul 2020 06:46:03 +0000 [thread overview]
Message-ID: <20200724064603.GA8449@lst.de> (raw)
In-Reply-To: <20200723153025.GF3307@localhost.localdomain>
On Thu, Jul 23, 2020 at 12:30:25PM -0300, Marcelo Ricardo Leitner wrote:
> On Thu, Jul 23, 2020 at 11:22:38AM +0200, Christoph Hellwig wrote:
> > On Wed, Jul 22, 2020 at 05:42:31PM -0300, Marcelo Ricardo Leitner wrote:
> > > Cc'ing linux-sctp@vger.kernel.org.
> >
> > What do you think of this version, which I think is a little cleaner?
>
> It splits up the argument parsing from the actual handling, ok. Looks
> good. Just one point:
>
> > +static int sctp_setsockopt_delayed_ack(struct sock *sk,
> > + struct sctp_sack_info *params,
> > + unsigned int optlen)
> > +{
> > + if (optlen = sizeof(struct sctp_assoc_value)) {
> > + struct sctp_sack_info p;
> > +
> > + pr_warn_ratelimited(DEPRECATED
> > + "%s (pid %d) "
> > + "Use of struct sctp_assoc_value in delayed_ack socket option.\n"
> > + "Use struct sctp_sack_info instead\n",
> > + current->comm, task_pid_nr(current));
> > +
> > + memcpy(&p, params, sizeof(struct sctp_assoc_value));
> > + p.sack_freq = p.sack_delay ? 0 : 1;
>
> Please add a comment saying that sctp_sack_info.sack_delay maps
> exactly to sctp_assoc_value.assoc_value, so that's why we can do
> memcpy and read assoc_value as sack_delay. I think it will help us not
> trip on this again in the future.
Yeah. Actually I think I'll go all the way and kill the not very
obvious or type safe memcpy as well.
prev parent reply other threads:[~2020-07-24 6:46 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <5955bc857c93d4bb64731ef7a9e90cb0094a8989.1595450200.git.marcelo.leitner@gmail.com>
2020-07-22 20:42 ` [PATCH net-next] sctp: fix slab-out-of-bounds in SCTP_DELAYED_SACK processing Marcelo Ricardo Leitner
2020-07-23 9:22 ` Christoph Hellwig
2020-07-23 15:30 ` Marcelo Ricardo Leitner
2020-07-24 6:46 ` Christoph Hellwig [this message]
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