From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.222.44 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792598935; b=MS8TYY0lJaJ4K1UjvOwlhDm1vjJLxaI6gCvDtbgRq/2EzwjQR+D+6owcLAT8fiFCGsUQ EblgJQDIkXtNFv88ZLGl6RXQ3YJMH1P74OlV3UnMWh2dg8A2RNEa6JsjVVOyLdNwZFBCh JNw8wkpgfsbY9KLS+UONijaHQ98OpHBSW/wlxI7yL6Ej7/L/YPcs3JZjyxg9FxBrbP2cx mPouvogR4MLP5uxDHPaj3B1vmwplW1RL6F7+PZqC8FKBXOohvzbcAe6FUnqPheFV6YDjs uj0+oZR0+vHJOPeL82k94waGObOLIQEuD7HlOL1UW+IGlZ6OLvmgCyY3kXxIJkOVweQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792598935; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Gm-Gg:X-Received:Received: Date:From:To:Cc:Message-ID:In-Reply-To:References:Subject: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=xlUjPkBFZR5E69M180zZ7SvybteIZBcwvq7YyxzDeRI=; b=TzsMaHOQUbqr24OakkMsB0UwxLZ3Dv86w7KaW44/WYXS1d+dYYNWnSd/C91t4kSC0mDi aU+QHA1Lo76GPlxkEzKVlXYchbOHgmUwPeaQ/B/IvRrqbjyXOFaCG37UGVyaz6GvQSJpB YRzam80F6RqJTM1lMgwP46xnLuYw8qfChWSN+gLGzKvQANyt5fU0+OVJYl5iAS24n4EVE NZ/GlcWhCTVJtFGx3Zop8T5mxdyj6+OlZsScv0iPPIldVKEgqZIItt9SN4+487KZOupCh KkdwfV7rkWBRMVaY69vuT+Yticx6szLL+TxY3hIocKQJN0imugqGUBp6lqC0K/jF3hg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20251104 header.b=HmkvCJ0v; arc=none smtp.remote-ip=209.85.222.44 Received: from mail-ua1-f44.google.com (mail-ua1-f44.google.com [209.85.222.44]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 558B3606A31B for ; Wed, 21 Oct 2026 16:08:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 558B3606A31B Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20251104 header.b=HmkvCJ0v Received: by mail-ua1-f44.google.com with SMTP id a1e0cc1a2514c-9902a746546so29193241.1 for ; Wed, 21 Oct 2026 09:08:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1792598934; x=1793203734; darn=vger.kernel.org; h=content-transfer-encoding:content-type:mime-version:subject :references:in-reply-to:message-id:cc:to:from:date:from:to:cc :subject:date:message-id:reply-to:content-type; bh=xlUjPkBFZR5E69M180zZ7SvybteIZBcwvq7YyxzDeRI=; b=HmkvCJ0vaUoa3UQ9+bVmx9GYBeGHPBtlOLf0CTWX9WnMkwRafYNyOSLx/EqFn7xC0z FeBLtVw9Bz3lADjseMfn9oWHJIVBJFAk99ataSjSPJQ4In6UetErxE16KChScPekSOyw MjpI/XW4ARjyQ8uPN8cvX8u8hYvhwIw4umZj2dxBiVOtWqSaa9fwYG3a201xAy+AR3CY 3AVX/nMuip49a0S77opD1Ad+JdBVu/RlOSXBN/Vb0/zuJ8lHgUed1jUyiMv492+qc6lw 5BvuP1Yi5jTt7Y3apvAZncY2fEhGdxDTG0tcV24vI3so6jisVt42aq9HO4FLaNKopDfA kgFQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1792598934; x=1793203734; h=content-transfer-encoding:content-type:mime-version:subject :references:in-reply-to:message-id:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=xlUjPkBFZR5E69M180zZ7SvybteIZBcwvq7YyxzDeRI=; b=o2XKG6qmINoaoBtLqmnWtL/kJgcx5TYJxn73RXhl5XGPGRdOXfCO0WVk3bJEkIC+9b o0ngGwgAMOWiWk2XNHlKyu2C4DEc4LaKRmTerrf76XBm/zk4G9sgqySI+1dQSZciAbRe HOiRSfNTYj0iVEA/fEC3Rnh0gw+/nw4rK85tEK3Wk8FWpKDJK9YEB+5rJG1+hkTIUWsd 6W0B2MsPG/Q3O71roiMc3PHvNESZcI0McuHGel4aFo57RTMhdIu6DfEcvcvqimsNEn2A qI680LDpl+yZ2k8LDV9QTRxEr0vfz3bnV/FPILvgMfDeE7qa/4vye12oQlvQv2s/UV1A 49hw== X-Forwarded-Encrypted: i=1; AKwUvByziXjClYTdnLhPDuEZ71fw6dlRCDtmhaH+YQM5isgGXiR/u9enxCuldluOUZQTLIHTnZhhxSbNzB/oK90=@vger.kernel.org X-Gm-Message-State: AFq9FYK1rYIUr8KCc6cxZzOntvUo5CGpeNd9mpnB9LXxVVS1ceMWf1Rg aE1Er+5s5FVnH9japSSQPGj8HOUEP4z85asmNZYP941yFm8mwCfwOFc/ X-Gm-Gg: AYBFou2Vgw/SSnccCU0KjrNxYcyIlM/S2jgPIH+r1j8fFvHM6WvOus9ulnnA0ZF5dMZ MNX2R4fx8vqEffKxVGzXxISYTYX5t1wGvVKjGi95FwIieE/+C0jZflHNQHJDh4mquMmCvPNhLsk H+s/nCR+fmOCsH9hv6W/weKcSqND+1Prbcu1Hy63fhCE6lE5R0UUgoMg6oR3y8u7ZbV7Q0XvaRT baTxqRFX2kuBIgHpuJipStzXsRqBTvxfrG2gcV7tFgLPvc8uplGAqv/RDAfPTP84ZW1FQZV3VN7 xqiD7Axiwz9NO8vct3nKMEOEIcK9hd/j+H5DGWB5aOKY9EZyZioEsB7vjH3ExxD4/gfM5AT71kq dlJZisNYg5ATJO19QQeU9YZcMqcKGGDCKfJDYZOzBS8frvCKf08ecg6KZKND0P31/yho1wxremz LMBGp0WDbA2ToZqK1DEjjsHyIzeTyTs79ERtHmPmBhszYM5yHYBRTnJRrVF1EYg+m69jRjl1UMF aeFAyvMg9ZZkIw0x1Y+F4HnjkNkn0FwdAK+x4VX3//pf+JIvllY7CHXo7hKF1HnJ2sVbuQHq17L RVSNjqbIlhLglXREjQv+o97gsIVmL47OL66PU/k+nTotj9To7JDJ3RIEDilOWuG0Wh8MG88z5JA +0cVQ/pvOrq/B6MUwQ64= X-Received: by 2002:a05:6102:21cd:b0:7ca:9674:a58f with SMTP id ada2fe7eead31-7cc7bcdf51amr1136476137.32.1792598934205; Wed, 21 Oct 2026 09:08:54 -0700 (PDT) Received: from gmail.com (111.46.245.35.bc.googleusercontent.com. [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-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit 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