From: Jakub Kicinski <kuba@kernel.org>
To: Peilin Ye <yepeilin.cs@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
David Ahern <dsahern@kernel.org>,
Peilin Ye <peilin.ye@bytedance.com>,
Cong Wang <cong.wang@bytedance.com>,
Feng Zhou <zhoufeng.zf@bytedance.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net 2/2] ip6_gre: Fix skb_under_panic in __gre6_xmit()
Date: Fri, 15 Apr 2022 19:11:33 +0200 [thread overview]
Message-ID: <20220415191133.0597a79a@kernel.org> (raw)
In-Reply-To: <20220414200854.GA2729@bytedance>
On Thu, 14 Apr 2022 13:08:54 -0700 Peilin Ye wrote:
> > We should also reject using SEQ with collect_md, but that's a separate
> > issue.
>
> Could you explain this a bit more? It seems that commit 77a5196a804e
> ("gre: add sequence number for collect md mode.") added this
> intentionally.
Interesting. Maybe a better way of dealing with the problem would be
rejecting SEQ if it's not set on the device itself.
When the device is set up without the SEQ bit enabled it disables Tx
locking (look for LLTX). This means that multiple CPUs can try to do
the tunnel->o_seqno++ in parallel. Not catastrophic but racy for sure.
next prev parent reply other threads:[~2022-04-15 17:11 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-11 22:32 [PATCH net 1/2] ip6_gre: Avoid updating tunnel->tun_hlen in __gre6_xmit() Peilin Ye
2022-04-11 22:33 ` [PATCH net 2/2] ip6_gre: Fix skb_under_panic " Peilin Ye
2022-04-14 11:14 ` Jakub Kicinski
2022-04-14 20:08 ` Peilin Ye
2022-04-15 17:11 ` Jakub Kicinski [this message]
2022-04-16 6:56 ` Peilin Ye
2022-04-16 7:33 ` Jakub Kicinski
2022-04-16 8:16 ` Peilin Ye
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=20220415191133.0597a79a@kernel.org \
--to=kuba@kernel.org \
--cc=cong.wang@bytedance.com \
--cc=davem@davemloft.net \
--cc=dsahern@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=peilin.ye@bytedance.com \
--cc=yepeilin.cs@gmail.com \
--cc=yoshfuji@linux-ipv6.org \
--cc=zhoufeng.zf@bytedance.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 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).