From: Jakub Kicinski <jakub.kicinski@netronome.com>
To: Eric Dumazet <edumazet@google.com>
Cc: "David S . Miller" <davem@davemloft.net>,
netdev <netdev@vger.kernel.org>,
Eric Dumazet <eric.dumazet@gmail.com>,
Michal Kubecek <mkubecek@suse.cz>, Firo Yang <firo.yang@suse.com>
Subject: Re: [PATCH net v2] tcp/dccp: fix possible race __inet_lookup_established()
Date: Fri, 13 Dec 2019 21:45:22 -0800 [thread overview]
Message-ID: <20191213214522.6b48065a@cakuba.netronome.com> (raw)
In-Reply-To: <20191214022041.75340-1-edumazet@google.com>
On Fri, 13 Dec 2019 18:20:41 -0800, Eric Dumazet wrote:
> Michal Kubecek and Firo Yang did a very nice analysis of crashes
> happening in __inet_lookup_established().
>
> Since a TCP socket can go from TCP_ESTABLISH to TCP_LISTEN
> (via a close()/socket()/listen() cycle) without a RCU grace period,
> I should not have changed listeners linkage in their hash table.
>
> They must use the nulls protocol (Documentation/RCU/rculist_nulls.txt),
> so that a lookup can detect a socket in a hash list was moved in
> another one.
>
> Since we added code in commit d296ba60d8e2 ("soreuseport: Resolve
> merge conflict for v4/v6 ordering fix"), we have to add
> hlist_nulls_add_tail_rcu() helper.
>
> Fixes: 3b24d854cb35 ("tcp/dccp: do not touch listener sk_refcnt under synflood")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: Michal Kubecek <mkubecek@suse.cz>
> Reported-by: Firo Yang <firo.yang@suse.com>
> Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
> Link: https://lore.kernel.org/netdev/20191120083919.GH27852@unicorn.suse.cz/
Applied, and queued for stable, thank you!
prev parent reply other threads:[~2019-12-14 5:45 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-14 2:20 [PATCH net v2] tcp/dccp: fix possible race __inet_lookup_established() Eric Dumazet
2019-12-14 5:45 ` Jakub Kicinski [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=20191213214522.6b48065a@cakuba.netronome.com \
--to=jakub.kicinski@netronome.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=eric.dumazet@gmail.com \
--cc=firo.yang@suse.com \
--cc=mkubecek@suse.cz \
--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).