From patchwork Mon Nov 25 06:08:05 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 13884426 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id ECA99D3B7DC for ; Mon, 25 Nov 2024 06:09:12 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tFSH8-0007Lj-8H; Mon, 25 Nov 2024 01:08:47 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tFSGy-0007KY-8X for qemu-devel@nongnu.org; Mon, 25 Nov 2024 01:08:36 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tFSGw-0000Q6-Og for qemu-devel@nongnu.org; Mon, 25 Nov 2024 01:08:35 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1732514914; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=cxBhyD2ijXQL3F0b7xO5gFtSbGmcT88xyErZV1LJs7Y=; b=bwlOYMajhe007Ht1ZQtKeZU9rDUOleXUntHASjJzSnR6TqmUCOWQH3R18JQfkCtrRalS7e Q6cBVA+T7zYMoCt7q+eS/JDqH8DUx5YaPeDwsJH2QYgcXs57B9s1xsHyjo7Cr5kAquIK8u mq6tJtkO9we/YF1O1dtbnMmMHyD3QyM= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-44-84ZwYjwKPlSQY3AU-RqArA-1; Mon, 25 Nov 2024 01:08:30 -0500 X-MC-Unique: 84ZwYjwKPlSQY3AU-RqArA-1 X-Mimecast-MFC-AGG-ID: 84ZwYjwKPlSQY3AU-RqArA Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 56E961955DC4; Mon, 25 Nov 2024 06:08:28 +0000 (UTC) Received: from localhost.localdomain (unknown [10.72.112.241]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id CC2B930000DF; Mon, 25 Nov 2024 06:08:22 +0000 (UTC) From: Jason Wang To: qemu-devel@nongnu.org Cc: Akihiko Odaki , qemu-stable@nongnu.org, Jason Wang Subject: [PULL 2/6] virtio-net: Fix size check in dhclient workaround Date: Mon, 25 Nov 2024 14:08:05 +0800 Message-ID: <20241125060809.15543-3-jasowang@redhat.com> In-Reply-To: <20241125060809.15543-1-jasowang@redhat.com> References: <20241125060809.15543-1-jasowang@redhat.com> MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=jasowang@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Akihiko Odaki work_around_broken_dhclient() accesses IP and UDP headers to detect relevant packets and to calculate checksums, but it didn't check if the packet has size sufficient to accommodate them, causing out-of-bound access hazards. Fix this by correcting the size requirement. Fixes: 1d41b0c1ec66 ("Work around dhclient brokenness") Cc: qemu-stable@nongnu.org Signed-off-by: Akihiko Odaki Signed-off-by: Jason Wang --- hw/net/virtio-net.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 75b4a28fb3..a2a8d6b07b 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -1697,8 +1697,11 @@ static void virtio_net_hdr_swap(VirtIODevice *vdev, struct virtio_net_hdr *hdr) static void work_around_broken_dhclient(struct virtio_net_hdr *hdr, uint8_t *buf, size_t size) { + size_t csum_size = ETH_HLEN + sizeof(struct ip_header) + + sizeof(struct udp_header); + if ((hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && /* missing csum */ - (size > 27 && size < 1500) && /* normal sized MTU */ + (size >= csum_size && size < 1500) && /* normal sized MTU */ (buf[12] == 0x08 && buf[13] == 0x00) && /* ethertype == IPv4 */ (buf[23] == 17) && /* ip.protocol == UDP */ (buf[34] == 0 && buf[35] == 67)) { /* udp.srcport == bootps */