From: Florian Westphal <fw@strlen.de>
To: Tamaki Yanagawa <ty@000ty.net>
Cc: netfilter-devel@vger.kernel.org, pablo@netfilter.org,
phil@nwl.cc, coreteam@netfilter.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH nf] netfilter: nfnetlink_queue: unclone skb before writing NFQA_L2HDR
Date: Sat, 7 Nov 2026 17:17:00 +0100 [thread overview]
Message-ID: <au9O_KyLej8ckT5V@strlen.de> (raw)
In-Reply-To: <20261107160517.726-1-ty@000ty.net>
Tamaki Yanagawa <ty@000ty.net> wrote:
> nfqa_parse_bridge() copies the NFQA_L2HDR attribute over the mac header
> of the queued skb in place. Bridge flooding queues clones that share
> their data with the copies sent to the other ports, so the rewritten
> header also shows up on frames that never went through the queue, and
> is changed while those may already be in transmission. Unclone the skb
> before the copy, as nfqnl_mangle() does for NFQA_PAYLOAD via
> skb_ensure_writable().
Can you explain in changelog why full unclone is needed rather than
skb_ensure_writable()?
next prev parent reply other threads:[~2026-11-07 16:17 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-07 16:05 Tamaki Yanagawa
2026-11-07 16:17 ` Florian Westphal [this message]
2026-11-07 16:32 ` Tamaki Yanagawa
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