From nobody Wed Oct 8 19:23:10 2025 Received: from mail-pl1-f172.google.com (mail-pl1-f172.google.com [209.85.214.172]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 918AD2D23B8; Wed, 25 Jun 2025 16:10:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750867836; cv=none; b=RAm4UXj0ueWtNz76IDgg4CrjdH485n1B3dhaJ5zo3aw4TElm8qwtuLN7CYZvaFIfiuHcvTLWEKV3kcDyB6G04NtnJIfVELlYiSREKiVdZ55K9iwvwvVnN/Ea3I/C1SSok6tQDJSPf3tZZP+D5j4Vc8SWFunNhjuz89xYp5Kq0Go= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750867836; c=relaxed/simple; bh=4VNy85BUiywaXD9Mqe5C4cqxPjoK22ldzoO5xhVanSM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EyeqXLCj/396WSWc7iodwo+Vz7COGpE0qE0iAWHgpLHi0Pnar7GIndihj9JBoX32kFS7ZGNCKjrereXQUHWSsiyqMThSA+Eyllfi5kK1fHuuPY5l8jgqYaasVcWrzTAGzwjP3P7iQ9/MQDLLoaxxei89LQsUZkpdm+66LTOeoYs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=STfFHJI9; arc=none smtp.client-ip=209.85.214.172 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) header.d=gmail.com header.i=@gmail.com header.b="STfFHJI9" Received: by mail-pl1-f172.google.com with SMTP id d9443c01a7336-236192f8770so1267345ad.0; Wed, 25 Jun 2025 09:10:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1750867833; x=1751472633; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=uU4X+SI62dfgcKBBMkPrylaI2hont+JORdjl4bJDSKE=; b=STfFHJI9u7nIjbrJSCc8v9Xlo5N+fTxOdgtg5PS+yCiCejcglsyizZG89o+irTib7D hjOhoJqbvhZHA0Fb/26Qv2Qi77J0BTyugL/QWgBDt0lj5rTikhF29JETkIvb9cCA9l9i 1EnkE98GLhZ2sC3h6P2pnXOObjoJCsrt2mfeC0Y5FhyOuiGhVVOlZEReU+JOBM0mXLVS jHL6M9CxX/8V9yJEmsSOOsMpdJcYaf1KXYO/qT6uCRWctiBCartKTsl7LVTawaq38qzQ L7Tc8S4QjefQS9L2UjI65OVzoSmrmmhVuUvpgRBAgX/N1TW6dQNTirCVWaSNLX7uxLJx /DjQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1750867833; x=1751472633; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=uU4X+SI62dfgcKBBMkPrylaI2hont+JORdjl4bJDSKE=; b=rZ3x1QciRdo+q4Bvy8UhT+feco/Bs9o0XU+69oc06rCVMjljrAylIUrppYwXGcGNky LCUGHzPFSEd3dccNFWudSGNpJLNchR4uWqNxyYapl4cqb3u8XL9tvoYGAmmYCk417StZ JKzPVEgC3b8T5J/SEj5hn3H5Egr86StXk4NVIgaHpnoM4ATbgc8Mi00MIVGBaQ2SRSg+ U3ARRQyTsaK73ue38EVfH0ZkcH5NvQy7DsNeq4jDU1sX4uBAqszLaAoqM7N9Q02qkIZE 51L6J6Gayb/B/3793+jMhrCoh4Ch5uRXHXm1A2ZmldPVlK1DYFoNMM5cqpel09wjiMfs AUug== X-Forwarded-Encrypted: i=1; AJvYcCVFVhbdEV1Sgwcbqmk4Ont9qyzOVefS/QqmP8sUijkMb2BxokEHYP2rdt1nORClvGKQSUFQZ4qfFUNSVXV8@vger.kernel.org, AJvYcCXO0mhP0Hxo4uVWrpzZWI5Qq0CQqmyL4uoppS5kKgcRmsbIDko5SPFnVgh21gbSlCp8NQs=@vger.kernel.org X-Gm-Message-State: AOJu0YwBoHq+c/0ih3JuxKDkwZE0Un6oVtgCa3Xy3oiGOTET7NXgSLrA Pv2dwp9U/o1WCN78bjuJxTbxLVWeDQRrl835MWzn90wyZbs6xo0dn08e+AvDew== X-Gm-Gg: ASbGncshMY9g3DPHBpTCRVGihv3WLH8ty988n2scoWRznXlqccHxr4oWrffDGvue0m/ Ez/W67JX5WvmdNvmdPyAytZpfb0Uq/+Gb8cPa46v+1/M1G1xtW69udIwuZWjKyCsDcVZrYiJdHk 17xBL1jnIkvBqytGdavDblWikQnj0y007SMJVSA0byvA9DJTbS+m3C+SygI9Mcv1ymomLttOVTe fcxRbbk3LG/mJcXohr2yoBD8yPicrIjMdDsuSbea6/CoCsU5H4hPO/sSHHMwoFf6UTvsaRl/6c0 WuD+C/FBy/1CTQARAT/2/VyT6XMIB/4+BbSPcRVOBD23h4mSA7RswLTxgPrNBqA6v0DqMCvp8FI p/g== X-Google-Smtp-Source: AGHT+IEtOCWRRtycCWE6b2ddeIkB621raQHnk3klmvycYJo2xwdbq//kpd/UA+wGQ7RO8gQtx2zEWA== X-Received: by 2002:a17:902:8212:b0:221:751f:cfbe with SMTP id d9443c01a7336-2390a4e1c2fmr1517585ad.19.1750867833222; Wed, 25 Jun 2025 09:10:33 -0700 (PDT) Received: from minh.192.168.1.1 ([2001:ee0:4f0e:fb30:1cf0:45c2:bdd1:b92d]) by smtp.googlemail.com with ESMTPSA id d9443c01a7336-237d873845esm143219175ad.243.2025.06.25.09.10.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Jun 2025 09:10:32 -0700 (PDT) From: Bui Quang Minh To: netdev@vger.kernel.org Cc: "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , =?UTF-8?q?Eugenio=20P=C3=A9rez?= , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Stanislav Fomichev , virtualization@lists.linux.dev, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, Bui Quang Minh Subject: [PATCH net 3/4] virtio-net: create a helper to check received mergeable buffer's length Date: Wed, 25 Jun 2025 23:08:48 +0700 Message-ID: <20250625160849.61344-4-minhquangbui99@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250625160849.61344-1-minhquangbui99@gmail.com> References: <20250625160849.61344-1-minhquangbui99@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Currently, we have repeated code to check the received mergeable buffer's length with allocated size. This commit creates a helper to do that and converts current code to use it. Signed-off-by: Bui Quang Minh --- drivers/net/virtio_net.c | 68 +++++++++++++++++----------------------- 1 file changed, 29 insertions(+), 39 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 6f9fedad4a5e..844cb2a78be0 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -778,6 +778,26 @@ static unsigned int mergeable_ctx_to_truesize(void *mr= g_ctx) return (unsigned long)mrg_ctx & ((1 << MRG_CTX_HEADER_SHIFT) - 1); } =20 +static int check_mergeable_len(struct net_device *dev, void *mrg_ctx, + unsigned int len) +{ + unsigned int headroom, tailroom, room, truesize; + + truesize =3D mergeable_ctx_to_truesize(mrg_ctx); + headroom =3D mergeable_ctx_to_headroom(mrg_ctx); + tailroom =3D headroom ? sizeof(struct skb_shared_info) : 0; + room =3D SKB_DATA_ALIGN(headroom + tailroom); + + if (len > truesize - room) { + pr_debug("%s: rx error: len %u exceeds truesize %lu\n", + dev->name, len, (unsigned long)(truesize - room)); + DEV_STATS_INC(dev, rx_length_errors); + return -1; + } + + return 0; +} + static struct sk_buff *virtnet_build_skb(void *buf, unsigned int buflen, unsigned int headroom, unsigned int len) @@ -1819,8 +1839,7 @@ static struct page *xdp_linearize_page(struct net_dev= ice *dev, page_off +=3D *len; =20 while (--*num_buf) { - unsigned int headroom, tailroom, room; - unsigned int truesize, buflen; + unsigned int buflen; void *buf; void *ctx; int off; @@ -1832,17 +1851,8 @@ static struct page *xdp_linearize_page(struct net_de= vice *dev, p =3D virt_to_head_page(buf); off =3D buf - page_address(p); =20 - truesize =3D mergeable_ctx_to_truesize(ctx); - headroom =3D mergeable_ctx_to_headroom(ctx); - tailroom =3D headroom ? sizeof(struct skb_shared_info) : 0; - room =3D SKB_DATA_ALIGN(headroom + tailroom); - - if (unlikely(buflen > truesize - room)) { + if (check_mergeable_len(dev, ctx, buflen)) { put_page(p); - pr_debug("%s: rx error: len %u exceeds truesize %lu\n", - dev->name, buflen, - (unsigned long)(truesize - room)); - DEV_STATS_INC(dev, rx_length_errors); goto err_buf; } =20 @@ -2143,7 +2153,6 @@ static int virtnet_build_xdp_buff_mrg(struct net_devi= ce *dev, struct virtnet_rq_stats *stats) { struct virtio_net_hdr_mrg_rxbuf *hdr =3D buf; - unsigned int headroom, tailroom, room; struct skb_shared_info *shinfo; unsigned int xdp_frags_truesz =3D 0; unsigned int truesize; @@ -2189,20 +2198,14 @@ static int virtnet_build_xdp_buff_mrg(struct net_de= vice *dev, page =3D virt_to_head_page(buf); offset =3D buf - page_address(page); =20 - truesize =3D mergeable_ctx_to_truesize(ctx); - headroom =3D mergeable_ctx_to_headroom(ctx); - tailroom =3D headroom ? sizeof(struct skb_shared_info) : 0; - room =3D SKB_DATA_ALIGN(headroom + tailroom); - - xdp_frags_truesz +=3D truesize; - if (unlikely(len > truesize - room)) { + if (check_mergeable_len(dev, ctx, len)) { put_page(page); - pr_debug("%s: rx error: len %u exceeds truesize %lu\n", - dev->name, len, (unsigned long)(truesize - room)); - DEV_STATS_INC(dev, rx_length_errors); goto err; } =20 + truesize =3D mergeable_ctx_to_truesize(ctx); + xdp_frags_truesz +=3D truesize; + frag =3D &shinfo->frags[shinfo->nr_frags++]; skb_frag_fill_page_desc(frag, page, offset, len); if (page_is_pfmemalloc(page)) @@ -2416,18 +2419,12 @@ static struct sk_buff *receive_mergeable(struct net= _device *dev, struct sk_buff *head_skb, *curr_skb; unsigned int truesize =3D mergeable_ctx_to_truesize(ctx); unsigned int headroom =3D mergeable_ctx_to_headroom(ctx); - unsigned int tailroom =3D headroom ? sizeof(struct skb_shared_info) : 0; - unsigned int room =3D SKB_DATA_ALIGN(headroom + tailroom); =20 head_skb =3D NULL; u64_stats_add(&stats->bytes, len - vi->hdr_len); =20 - if (unlikely(len > truesize - room)) { - pr_debug("%s: rx error: len %u exceeds truesize %lu\n", - dev->name, len, (unsigned long)(truesize - room)); - DEV_STATS_INC(dev, rx_length_errors); + if (check_mergeable_len(dev, ctx, len)) goto err_skb; - } =20 if (unlikely(vi->xdp_enabled)) { struct bpf_prog *xdp_prog; @@ -2462,17 +2459,10 @@ static struct sk_buff *receive_mergeable(struct net= _device *dev, u64_stats_add(&stats->bytes, len); page =3D virt_to_head_page(buf); =20 - truesize =3D mergeable_ctx_to_truesize(ctx); - headroom =3D mergeable_ctx_to_headroom(ctx); - tailroom =3D headroom ? sizeof(struct skb_shared_info) : 0; - room =3D SKB_DATA_ALIGN(headroom + tailroom); - if (unlikely(len > truesize - room)) { - pr_debug("%s: rx error: len %u exceeds truesize %lu\n", - dev->name, len, (unsigned long)(truesize - room)); - DEV_STATS_INC(dev, rx_length_errors); + if (check_mergeable_len(dev, ctx, len)) goto err_skb; - } =20 + truesize =3D mergeable_ctx_to_truesize(ctx); curr_skb =3D virtnet_skb_append_frag(head_skb, curr_skb, page, buf, len, truesize); if (!curr_skb) --=20 2.43.0