From: Florian Westphal <fw@strlen.de>
To: Vasily Averin <vvs@virtuozzo.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>,
Jozsef Kadlecsik <kadlec@netfilter.org>,
Florian Westphal <fw@strlen.de>,
netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH NETFILTER] netfilter: gre: nf_ct_gre_keymap_flush() removal
Date: Wed, 30 Jun 2021 11:54:01 +0200 [thread overview]
Message-ID: <20210630095401.GB18022@breakpoint.cc> (raw)
In-Reply-To: <cb5dbf85-302d-386d-7b57-b043063cea06@virtuozzo.com>
Vasily Averin <vvs@virtuozzo.com> wrote:
> nf_ct_gre_keymap_flush() is useless.
> It is called from nf_conntrack_cleanup_net_list() only and tries to remove
> nf_ct_gre_keymap entries from pernet gre keymap list. Though:
> a) at this point the list should already be empty, all its entries were
> deleted during the conntracks cleanup, because
> nf_conntrack_cleanup_net_list() executes nf_ct_iterate_cleanup(kill_all)
> before nf_conntrack_proto_pernet_fini():
> nf_conntrack_cleanup_net_list
> +- nf_ct_iterate_cleanup
> | nf_ct_put
> | nf_conntrack_put
> | nf_conntrack_destroy
> | destroy_conntrack
> | destroy_gre_conntrack
> | nf_ct_gre_keymap_destroy
> `- nf_conntrack_proto_pernet_fini
> nf_ct_gre_keymap_flush
>
> b) Let's say we find that the keymap list is not empty. This means netns
> still has a conntrack associated with gre, in which case we should not free
> its memory, because this will lead to a double free and related crashes.
> However I doubt it could have gone unnoticed for years, obviously
> this does not happen in real life. So I think we can remove
> both nf_ct_gre_keymap_flush() and nf_conntrack_proto_pernet_fini().
Acked-by: Florian Westphal <fw@strlen.de>
parent reply other threads:[~2021-06-30 9:54 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <cb5dbf85-302d-386d-7b57-b043063cea06@virtuozzo.com>]
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=20210630095401.GB18022@breakpoint.cc \
--to=fw@strlen.de \
--cc=coreteam@netfilter.org \
--cc=kadlec@netfilter.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netfilter-devel@vger.kernel.org \
--cc=pablo@netfilter.org \
--cc=vvs@virtuozzo.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).