From: john.p.donnelly@oracle.com
To: Florian Westphal <fw@strlen.de>
Cc: vegard.nossum@oracle.com, netdev@vger.kernel.org,
bridge@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
george.kennedy@oracle.com, syzkaller@googlegroups.com,
netfilter-devel@vger.kernel.org,
Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Subject: Re: [Bridge] [PATCH nf] netfilter: ebtables: reject blobs that don't provide all entry points
Date: Mon, 29 Aug 2022 09:10:10 -0500 [thread overview]
Message-ID: <bda042e0-8054-41f3-5df6-c39ad424cde2@oracle.com> (raw)
In-Reply-To: <20220829140320.GB27814@breakpoint.cc>
On 8/29/22 9:03 AM, Florian Westphal wrote:
> john.p.donnelly@oracle.com <john.p.donnelly@oracle.com> wrote:
>> On 8/20/22 12:35 PM, Florian Westphal wrote:
>>> For some reason ebtables reject blobs that provide entry points that are
>>> not supported by the table.
>>>
>>> What it should instead reject is the opposite, i.e. rulesets that
>>> DO NOT provide an entry point that is supported by the table.
>>>
>>> t->valid_hooks is the bitmask of hooks (input, forward ...) that will
>>> see packets. So, providing an entry point that is not support is
>>> harmless (never called/used), but the reverse is NOT, this will cause
>>> crash because the ebtables traverser doesn't expect a NULL blob for
>>> a location its receiving packets for.
>>>
>>> Instead of fixing all the individual checks, do what iptables is doing and
>>> reject all blobs that doesn't provide the expected hooks.
>>>
>>> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
>>> Reported-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
>>> Signed-off-by: Florian Westphal <fw@strlen.de>
>>
>> Hi,
>>
>> Could you please add the panic stack mentioned above and syzkaller
>> reproducer ID to the commit text ?
>
> I did not see a reproducer ID. What ended up in the tree is this:
>
> https://urldefense.com/v3/__https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7997eff82828304b780dc0a39707e1946d6f1ebf__;!!ACWV5N9M2RV99hQ!JxonjgQUi7Mbcd-ouxRwPgu8Jwl6ej2rO4pTvYMtteWexclV5-hciu9e5rgtkXoB7dyAdLCyZ4EQ9HQj$
Thank you !
prev parent reply other threads:[~2022-08-29 14:10 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-20 7:03 [Bridge] [PATCH] netfilter: ebtables: fix a NULL pointer dereference in ebt_do_table() Harshit Mogalapalli
2022-08-20 16:26 ` Florian Westphal
2022-08-20 19:18 ` [Bridge] [External] : " Harshit Mogalapalli
2022-08-20 17:35 ` [Bridge] [PATCH nf] netfilter: ebtables: reject blobs that don't provide all entry points Florian Westphal
2022-08-20 19:20 ` [Bridge] [External] : " Harshit Mogalapalli
2022-08-29 13:57 ` [Bridge] " john.p.donnelly
2022-08-29 14:03 ` Florian Westphal
2022-08-29 14:10 ` john.p.donnelly [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=bda042e0-8054-41f3-5df6-c39ad424cde2@oracle.com \
--to=john.p.donnelly@oracle.com \
--cc=bridge@lists.linux-foundation.org \
--cc=fw@strlen.de \
--cc=george.kennedy@oracle.com \
--cc=harshit.m.mogalapalli@oracle.com \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=netfilter-devel@vger.kernel.org \
--cc=syzkaller@googlegroups.com \
--cc=vegard.nossum@oracle.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 read-only IMAP folder(s) and NNTP newsgroup(s).