From mboxrd@z Thu Jan  1 00:00:00 1970
From: Florian Westphal <fw@strlen.de>
Subject: Re: ABI Breakage - nftnl_rule_parse_attr_cb
Date: Wed, 22 Jun 2022 17:55:59 +0200
Message-ID: <20220622155559.GA18555@breakpoint.cc>
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To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Kiernan George <kbg98@vt.edu>, netfilter@vger.kernel.org

Pablo Neira Ayuso <pablo@netfilter.org> wrote:
> On Wed, Jun 22, 2022 at 09:24:25AM -0400, Kiernan George wrote:
> > This is the relevant line where I build my header:
> > nlh = nftnl_rule_nlmsg_build_hdr(mnl_nlmsg_batch_current(batch),
> > NFT_MSG_NEWRULE, family, NLM_F_APPEND | NLM_F_EXCL | NLM_F_CREATE |
> > NLM_F_ECHO | NLM_F_ACK, seq++);
> > 
> > If I remove NLM_F_ECHO, it fixes my issue, but I would prefer to keep
> > this unless there is a better way to get the created rule's handle. I
> > also set the handle directly:
> > mnl_attr_put_u64(nlh, NFTNL_RULE_POSITION, htobe64(handle));
> 
> Makes no sense. Flags are irrelevant for the ABI breakage you are
> reporting. Send us a reproducer.

Probably corrupted or too-small receive buffer w. garbage fed into
netlink parser.

Impossible to say without reproducer.