All of lore.kernel.org
 help / color / mirror / Atom feed
From: Eric Dumazet <eric.dumazet@gmail.com>
To: Cong Wang <xiyou.wangcong@gmail.com>, netdev@vger.kernel.org
Cc: Eric Dumazet <edumazet@google.com>
Subject: Re: [Patch net] net: drop skb on failure in ip_check_defrag()
Date: Thu, 1 Nov 2018 12:08:40 -0700	[thread overview]
Message-ID: <4d4d6572-b6ec-edaf-d88e-5097d1b4cb1c@gmail.com> (raw)
In-Reply-To: <20181101190237.10830-1-xiyou.wangcong@gmail.com>



On 11/01/2018 12:02 PM, Cong Wang wrote:
> Most callers of pskb_trim_rcsum() simply drop the skb when
> it fails, however, ip_check_defrag() still continues to pass
> the skb up to stack. This is suspicious.
> 
> In ip_check_defrag(), after we learn the skb is an IP fragment,
> passing the skb to callers makes no sense, because callers expect
> fragments are defrag'ed on success. So, dropping the skb when we
> can't defrag it is reasonable.
> 
> Note, prior to commit 88078d98d1bb, this is not a big problem as
> checksum will be fixed up anyway. After it, the checksum is not
> correct on failure.
> 
> Found this during code review.
> 
> Fixes: 88078d98d1bb ("net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends")
> Cc: Eric Dumazet <edumazet@google.com>
> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>

Thanks Cong !

Reviewed-by: Eric Dumazet <edumazet@google.com>

  reply	other threads:[~2018-11-02  4:12 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-01 19:02 [Patch net] net: drop skb on failure in ip_check_defrag() Cong Wang
2018-11-01 19:08 ` Eric Dumazet [this message]
2018-11-01 20:56 ` David Miller

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=4d4d6572-b6ec-edaf-d88e-5097d1b4cb1c@gmail.com \
    --to=eric.dumazet@gmail.com \
    --cc=edumazet@google.com \
    --cc=netdev@vger.kernel.org \
    --cc=xiyou.wangcong@gmail.com \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.