From patchwork Fri Dec 14 22:34:43 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jim Mattson X-Patchwork-Id: 10731769 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0AA0413AD for ; Fri, 14 Dec 2018 22:35:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AB2C22D787 for ; Fri, 14 Dec 2018 22:35:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9CF362D78F; Fri, 14 Dec 2018 22:35:00 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2C2852D787 for ; Fri, 14 Dec 2018 22:35:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729707AbeLNWe6 (ORCPT ); Fri, 14 Dec 2018 17:34:58 -0500 Received: from mail-vs1-f74.google.com ([209.85.217.74]:47909 "EHLO mail-vs1-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729341AbeLNWe6 (ORCPT ); Fri, 14 Dec 2018 17:34:58 -0500 Received: by mail-vs1-f74.google.com with SMTP id y139so3224210vsc.14 for ; Fri, 14 Dec 2018 14:34:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=YPH6TPsgMa/4T66cYZq3Q+uaX57wZSk4vAaYPUfD3Mc=; b=AL97G6m0syEAq5O117TpvaUdLv9SaHuI299ZEMIZL/QULctReItzVkdTilTiRaAUCY zVZxRnT23pC0ETYvdSxl/RdLPpuJNSWF6SuDoDNDeo6semx/9u4p5ovf6ij6pFOg59RG dbVqtTrs8Z4nUf38C46hMAVB87n4LyjyogiaxflojAoEfpEODb3JhVqjidBqnyndH8uM cDZcUGgjS1oXPLIsDRMTIgiCYDlznro65lCQ6wxJ/IuNLk9Wj1TsZXqHlakG/Tq+LpPd fzbAbEv8rmMTRVuuc27Po2mXfqstrdTvZZw8sje5yj7w10C94tGZdkAZ87e7vMO0z6B6 1aHw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=YPH6TPsgMa/4T66cYZq3Q+uaX57wZSk4vAaYPUfD3Mc=; b=dSKuysD3GwwQAczQG44pD3T+8or656BBPF9xQs+20J0vbflWckzDmcU6vhnokzv+YX 4HBFORCDYonrQZDgBevIboCZeCfjr3P4vujEIkB/6HmO7eXXQEp11buCCpqxtPXZ9tmr 0MiECnJOeMEtEp3K35FUuXNjTplZLgTovP8Fxh8fIWtHYCna9t0qq44h965BqFtSn/WH 9G3RoI8HH9sNtEe5zRgiL7qPlSVcojXgR4nfyO4WpPneWGNR2LjbPpdxNnfRtKwVW1Ni zB6anfve8QDD5EW7B/mSb+NplKh0Uj//z0VaUx7g4puCwPH8PHznUABr32C4eFcC99rS IvZw== X-Gm-Message-State: AA+aEWYq6e9kLnzxufoB3zMDDWn/pdQIRdZdwyes/kDVHzqDpRnayBTf Sc6m7Ke+MaXtyFHfrI2jinmCaBvuKg25pPc26wY298TCpdRjJmX1omyr7P3C0pHANdQpiZKkOIC yA9J9ANdXedmuB+VtytKjQIgNUXdPl0EjXbhzqFCSWrYbCFjqmgdagfK8jJ8ew4U= X-Google-Smtp-Source: AFSGD/XnVBuZfbrt0SUNlXuZ7gkvdysgSJjM/IBs78KuKgp4ZTsH/Bw/jLpI52mGYX/LISsFmO/ss1oO48K36g== X-Received: by 2002:a1f:abcf:: with SMTP id u198mr4646337vke.21.1544826897168; Fri, 14 Dec 2018 14:34:57 -0800 (PST) Date: Fri, 14 Dec 2018 14:34:43 -0800 In-Reply-To: <20181214203239.GH22063@linux.intel.com> Message-Id: <20181214223443.153614-1-jmattson@google.com> Mime-Version: 1.0 References: <20181214203239.GH22063@linux.intel.com> X-Mailer: git-send-email 2.20.0.405.gbc1bbc6f85-goog Subject: [PATCH v2] kvm: Change offset in kvm_write_guest_offset_cached to unsigned From: Jim Mattson To: kvm@vger.kernel.org Cc: Jim Mattson , Cfir Cohen , Peter Shier , Krish Sadhukhan , Sean Christopherson Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Since the offset is added directly to the hva from the gfn_to_hva_cache, a negative offset could result in an out of bounds write. The existing BUG_ON only checks for addresses beyond the end of the gfn_to_hva_cache, not for addresses before the start of the gfn_to_hva_cache. Note that all current call sites have non-negative offsets. Fixes: 4ec6e8636256 ("kvm: Introduce kvm_write_guest_offset_cached()") Reported-by: Cfir Cohen Signed-off-by: Jim Mattson Reviewed-by: Cfir Cohen Reviewed-by: Peter Shier Reviewed-by: Krish Sadhukhan Reviewed-by: Sean Christopherson --- include/linux/kvm_host.h | 3 ++- virt/kvm/kvm_main.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index c926698040e0d..a03d5e264e5e7 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -694,7 +694,8 @@ int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data, int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, void *data, unsigned long len); int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, - void *data, int offset, unsigned long len); + void *data, unsigned int offset, + unsigned long len); int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc, gpa_t gpa, unsigned long len); int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 2679e476b6c39..065ee2fb40340 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1965,7 +1965,8 @@ int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc, EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init); int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, - void *data, int offset, unsigned long len) + void *data, unsigned int offset, + unsigned long len) { struct kvm_memslots *slots = kvm_memslots(kvm); int r;