From: Florian Westphal <fw@strlen•de>
To: Willem de Bruijn <willemdebruijn.kernel@gmail•com>
Cc: Eric Dumazet <edumazet@google•com>,
Florian Westphal <fw@strlen•de>,
netdev@vger•kernel.org, Paolo Abeni <pabeni@redhat•com>,
"David S. Miller" <davem@davemloft•net>,
Jakub Kicinski <kuba@kernel•org>,
netfilter-devel@vger•kernel.org, pablo@netfilter•org,
willemb@google•com, Christoph Paasch <cpaasch@apple•com>
Subject: Re: [PATCH net-next 1/2] net: add and use skb_get_hash_net
Date: Sun, 9 Jun 2024 00:17:30 +0200 [thread overview]
Message-ID: <20240608221730.GA13159@breakpoint.cc> (raw)
In-Reply-To: <6663159ab88ef_2f27b294c5@willemb.c.googlers.com.notmuch>
Willem de Bruijn <willemdebruijn.kernel@gmail•com> wrote:
> > > syzkaller did something like this:
> > > table inet filter {
> > > chain input {
> > > type filter hook input priority filter; policy accept;
> > > meta nftrace set 1 # calls skb_get_hash
> > > tcp dport 42 reject with tcp reset # emits skb with NULL skb dev/sk
> > > }
> > > chain output {
> > > type filter hook output priority filter; policy accept;
> > > # empty chain is enough
> > > }
> > > }
> > >
> > > ... then sends a tcp packet to port 42.
> > >
> > > Initial attempt to simply set skb->dev from nf_reject_ipv4 doesn't cover
> > > all cases: skbs generated via ipv4 igmp_send_report trigger similar splat.
>
> Does this mean we have more non-nf callsites to convert?
There might be non-nf call sites that need skb_get_hash_net(),
but I don't know of any.
The above comment was meant to say that I tried to patch this
outside of flow dissector by setting skb->dev properly in nf_reject,
but that still triggers a slightly different WARN trace, this time
due to igmp_send_report also sending skb without dev+sk pointers.
next prev parent reply other threads:[~2024-06-08 22:53 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-07 8:31 [PATCH net-next 0/2] net: flow dissector: allow explicit passing of netns Florian Westphal
2024-06-07 8:31 ` [PATCH net-next 1/2] net: add and use skb_get_hash_net Florian Westphal
2024-06-07 9:25 ` Eric Dumazet
2024-06-07 14:13 ` Willem de Bruijn
2024-06-08 22:17 ` Florian Westphal [this message]
2024-06-07 12:33 ` kernel test robot
2024-06-07 8:32 ` [PATCH net-next 2/2] net: add and use __skb_get_hash_symmetric_net Florian Westphal
2024-06-07 9:26 ` Eric Dumazet
2024-06-07 14:14 ` Willem de Bruijn
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=20240608221730.GA13159@breakpoint.cc \
--to=fw@strlen$(echo .)de \
--cc=cpaasch@apple$(echo .)com \
--cc=davem@davemloft$(echo .)net \
--cc=edumazet@google$(echo .)com \
--cc=kuba@kernel$(echo .)org \
--cc=netdev@vger$(echo .)kernel.org \
--cc=netfilter-devel@vger$(echo .)kernel.org \
--cc=pabeni@redhat$(echo .)com \
--cc=pablo@netfilter$(echo .)org \
--cc=willemb@google$(echo .)com \
--cc=willemdebruijn.kernel@gmail$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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