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[35.245.46.111]) by smtp.gmail.com with ESMTPSA id a1e0cc1a2514c-990d0e0ba56sm3638029241.1.2026.10.21.09.08.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Oct 2026 09:08:52 -0700 (PDT) Date: Wed, 21 Oct 2026 12:08:52 -0400 From: Willem de Bruijn To: "Michael S. Tsirkin" , linux-kernel@vger.kernel.org Cc: Willem de Bruijn , Chris Arges , =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , Phil Sutter , Jason Wang , =?UTF-8?B?RXVnZW5pbyBQw6lyZXo=?= , Xuan Zhuo , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, virtualization@lists.linux.dev, Max Krasnyansky , Rusty Russell , Richard Weinberger , Anton Ivanov , Johannes Berg , linux-um@lists.infradead.org Message-ID: In-Reply-To: <26741a9a64c28e8de6d13e04972d296d89e1c95d.1792565282.git.mst@redhat.com> References: <26741a9a64c28e8de6d13e04972d296d89e1c95d.1792565282.git.mst@redhat.com> Subject: Re: [PATCH net v4 2/7] um: vector: trim skbs before verifying the header X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261021_090855_557558_C79CF1D0 X-CRM114-Status: UNSURE ( 8.73 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -2.1 (--) X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" X-Spam-Status: No, score=-7.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 Michael S. Tsirkin wrote: > The vector receive path over-allocates the skb and only trims it > to the received length after the transport header is verified. > > A follow up patch will complete the packet checksum in software within > virtio_net_hdr_to_skb so we need the packet trimmed (otherwise the > checksum would be computed incorrectly over the unreceived tail of the > buffer). > > Trim first, so the import sees the packet as it was received. > > Signed-off-by: Michael S. Tsirkin Reviewed-by: Willem de Bruijn