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Date: Sat, 13 Jun 2026 16:57:49 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Yiming Qian <yimingqian591@gmail.com>
Cc: security@kernel.org, John Fastabend <john.fastabend@gmail.com>, Jakub
 Sitnicki <jakub@cloudflare.com>, Sabrina Dubroca <sd@queasysnail.net>,
 "David S . Miller" <davem@davemloft.net>, Eric Dumazet
 <edumazet@google.com>, Paolo Abeni <pabeni@redhat.com>, Simon Horman
 <horms@kernel.org>, keenanat2000@gmail.com, netdev@vger.kernel.org,
 bpf@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH net v2] net: skmsg: preserve sg.copy across SG
 transforms
Message-ID: <20260613165749.32fbdae6@kernel.org>
In-Reply-To: <20260610062137.49075-1-yimingqian591@gmail.com>
References: <20260610062137.49075-1-yimingqian591@gmail.com>
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On Wed, 10 Jun 2026 06:21:36 +0000 Yiming Qian wrote:
> The sk_msg sg.copy bitmap is part of the scatterlist entry ownership
> state. A set bit tells sk_msg_compute_data_pointers() not to expose the
> entry through writable BPF ctx->data. This protects entries backed by
> pages that are not private to the sk_msg, such as splice-backed file
> page-cache pages.

Note to other maintainers: please don't commit this yet.
I will send a de-feature for TLS+sockmap to net-next,
if this is in the tree the CI won't ingest it (once CI
goes thru we can merge and fix the conflict).