From patchwork Wed Oct 12 16:59:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Ren X-Patchwork-Id: 13005224 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA7C1C4332F for ; Wed, 12 Oct 2022 16:59:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229941AbiJLQ7q (ORCPT ); Wed, 12 Oct 2022 12:59:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40714 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229680AbiJLQ7l (ORCPT ); Wed, 12 Oct 2022 12:59:41 -0400 Received: from mail-pg1-x52b.google.com (mail-pg1-x52b.google.com [IPv6:2607:f8b0:4864:20::52b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E3835FE92A for ; Wed, 12 Oct 2022 09:59:32 -0700 (PDT) Received: by mail-pg1-x52b.google.com with SMTP id f193so16086115pgc.0 for ; Wed, 12 Oct 2022 09:59:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=ewQpo6SyzsCd+TVr4dngzoh/1LumYtAxcdZG9494fvM=; b=DzwjZ6oCSiR0/0Xe5yTo5hS4sfi1Qf3T72pp5dGmxcxXxT6xgKZaRowQ0eOCKSrFqW NPdaBbujgUM/v4LsY4eYOoV9mqeKbBXdXgrtMXIxWXwmXqOaQvuuzsgwtUa1mtfkTirK qUXL4QjIF2PUCPNZtLlNPgFm8RHMOsURdLD2iKzmgASYJJNOSPZGG4np/+/BLiJ2dOxq qiS6tUSX80LtJvGXW/5SNO73P01DSDJCDa6w3qh3YGoQioZRJErV7wKiqVjTaN+56Uxu PCOEqIZf9emRspCJ9Xjwf0a8rOunDS1URjX8v3ap42r7l70bV5tCORGN49cTznXnV8mr oMQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=ewQpo6SyzsCd+TVr4dngzoh/1LumYtAxcdZG9494fvM=; b=VwGnhzI+hUlxK2nKbBBtJw58vdCFeoPRSkgtYmf350/XkxzvAIgVBqjYcHUBpSnTg0 ri2FaREEefqYkYgnAb2QNyxRimlBdmwqNatdpWXZU22OIVCkcr92KzYlAfh6saezQURS dDgd2O/q7RJ0SsuyCbV5vWhc5YRBCP0ci9dC1cyh8EAli7q6EoljSTZo9FFZerE8sDBl Vf+KmKtGKWLKUC1Rr4WPxGCqFPMurFgjsbZyb3aTl1VeKE+Q8iULcpJHTUJaXm4kvz5x zzoqzqhSz+s5BSeu1XgQUOJUj/Nmt5ICEQQQo5xwVFrZwaO271SO3TEbHycfQtYBgxTs R3Tg== X-Gm-Message-State: ACrzQf2i4dK1jZPIjM/eTcyTW5x6L3EuYZxj0IOkGIutasI9o4ciMAaz MGiBOhNDK4i20LYCAjqege8d6xEmuDoXOQ== X-Google-Smtp-Source: AMsMyM6QlAXDkvBArVj2SUglXYsmsrSFS9PDQRCfhtMH5c2TRBrdF5AGwHU929t3lHrPygD60k1epA== X-Received: by 2002:aa7:9057:0:b0:565:d7dd:a453 with SMTP id n23-20020aa79057000000b00565d7dda453mr305113pfo.33.1665593971047; Wed, 12 Oct 2022 09:59:31 -0700 (PDT) Received: from e69h04161.et15sqa.tbsite.net ([140.205.118.126]) by smtp.gmail.com with ESMTPSA id f8-20020a170902684800b0017534ffd491sm4462697pln.163.2022.10.12.09.59.29 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 12 Oct 2022 09:59:30 -0700 (PDT) From: Eric Ren To: kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu Cc: eric.auger@redhat.com, cdall@linaro.org, marc.zyngier@arm.com Subject: [PATCH] KVM: arm64: vgic: fix wrong loop condition in scan_its_table() Date: Thu, 13 Oct 2022 00:59:25 +0800 Message-Id: X-Mailer: git-send-email 1.8.3.1 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Reproducer hints: 1. Create ARM virt VM with pxb-pcie bus which adds extra host bridges, with qemu command like: ``` -device pxb-pcie,bus_nr=8,id=pci.x,numa_node=0,bus=pcie.0 \ -device pcie-root-port,..,bus=pci.x \ ... -device pxb-pcie,bus_nr=37,id=pci.y,numa_node=1,bus=pcie.0 \ -device pcie-root-port,..,bus=pci.y \ ... ``` 2. Perform VM migration which calls save/restore device tables. In that setup, we get a big "offset" between 2 device_ids ( one is small, another is big), which makes unsigned "len" round up a big positive number, causing loop to continue exceptionally. Signed-off-by: Eric Ren --- arch/arm64/kvm/vgic/vgic-its.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c index 24d7778d1ce6..673554ef02f9 100644 --- a/arch/arm64/kvm/vgic/vgic-its.c +++ b/arch/arm64/kvm/vgic/vgic-its.c @@ -2141,7 +2141,7 @@ static int scan_its_table(struct vgic_its *its, gpa_t base, int size, u32 esz, int start_id, entry_fn_t fn, void *opaque) { struct kvm *kvm = its->dev->kvm; - unsigned long len = size; + ssize_t len = size; int id = start_id; gpa_t gpa = base; char entry[ESZ_MAX];