From: David Miller <davem@davemloft.net>
To: edumazet@google.com
Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com
Subject: Re: [PATCH net] ipv4: frags: handle possible skb truesize change
Date: Tue, 31 Jul 2018 14:45:35 -0700 (PDT) [thread overview]
Message-ID: <20180731.144535.1317399050532306183.davem@davemloft.net> (raw)
In-Reply-To: <20180731045029.48957-1-edumazet@google.com>
From: Eric Dumazet <edumazet@google.com>
Date: Mon, 30 Jul 2018 21:50:29 -0700
> ip_frag_queue() might call pskb_pull() on one skb that
> is already in the fragment queue.
>
> We need to take care of possible truesize change, or we
> might have an imbalance of the netns frags memory usage.
>
> IPv6 is immune to this bug, because RFC5722, Section 4,
> amended by Errata ID 3089 states :
>
> When reassembling an IPv6 datagram, if
> one or more its constituent fragments is determined to be an
> overlapping fragment, the entire datagram (and any constituent
> fragments) MUST be silently discarded.
>
> Fixes: 158f323b9868 ("net: adjust skb->truesize in pskb_expand_head()")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
Applied and queued up for -stable.
Frankly, I think we should enforce the ipv6 rules for ipv4 too.
There is absolutely no reasonable situation where overlapping fragment
queue entries should arrive. None whatsoever.
prev parent reply other threads:[~2018-07-31 23:27 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-31 4:50 [PATCH net] ipv4: frags: handle possible skb truesize change Eric Dumazet
2018-07-31 21:45 ` David Miller [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180731.144535.1317399050532306183.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=eric.dumazet@gmail.com \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).