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Date: Sun, 10 May 2026 08:45:20 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Hyunwoo Kim <imv4bel@gmail.com>
Cc: dhowells@redhat.com, marc.dionne@auristor.com, davem@davemloft.net,
 edumazet@google.com, pabeni@redhat.com, horms@kernel.org,
 qingfang.deng@linux.dev, jiayuan.chen@linux.dev,
 linux-afs@lists.infradead.org, netdev@vger.kernel.org,
 stable@vger.kernel.org
Subject: Re: [PATCH net v3] rxrpc: Also unshare DATA/RESPONSE packets when
 paged frags are present
Message-ID: <20260510084520.476745b5@kernel.org>
In-Reply-To: <af2kdW2F1gJ9U-Gg@v4bel>
References: <af2kdW2F1gJ9U-Gg@v4bel>
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On Fri, 8 May 2026 17:53:09 +0900 Hyunwoo Kim wrote:
>  			    sp->hdr.securityIndex != 0 &&
> -			    skb_cloned(skb)) {
> +			    (skb_cloned(skb) ||
> +			     skb_has_frag_list(skb) ||
> +			     skb_has_shared_frag(skb))) {

We seem to be getting a lot of fixes for this issue, and this one is
incorrect :| Writing to _any_ frags is incorrect. You have to copy
if skb is not linear. skb_ensure_writable()