From patchwork Mon Jan 24 17:26:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tadeusz Struk X-Patchwork-Id: 12722512 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 5DB60C433F5 for ; Mon, 24 Jan 2022 17:26:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244601AbiAXR06 (ORCPT ); Mon, 24 Jan 2022 12:26:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51274 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244572AbiAXR05 (ORCPT ); Mon, 24 Jan 2022 12:26:57 -0500 Received: from mail-pl1-x634.google.com (mail-pl1-x634.google.com [IPv6:2607:f8b0:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B9398C06173B for ; Mon, 24 Jan 2022 09:26:56 -0800 (PST) Received: by mail-pl1-x634.google.com with SMTP id y17so5865882plg.7 for ; Mon, 24 Jan 2022 09:26:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=pIG7bqbcrRfwBrBEO23YURvyZTmv6ER+4jcJH0n36TE=; b=SToeYmIp5JOQZbs5CH+J4vKLppCYfB2k8jqDvBOFCk1hMN2PXv35OH1H5lwqw+uNqi nRQqcavTP4IGkcz7GZfdP95rl4VuOeNztobrcsuzGuHwft2m/WsigI/0D8eoQ2bVykUT Hn5XmyBOSw+R8O7fIgfS8KjpNie9lfJDWI713MJ42Ow4uQ6H99yf0hTaaFy4yO/wMJRn kNMf/xSkpOnYOEdZPiwtlLhp8rpbjYUM6Ej5rlDARTfDU2l7NcT+QbPE2R/VxqdIOzoR 2FlrGo1t8GvfJdj4GbPJBQbwzagclO5Gp4RMZVCOXMyNpnEnbD2Bu3sfcYQVZdmqS1hU 1lPg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=pIG7bqbcrRfwBrBEO23YURvyZTmv6ER+4jcJH0n36TE=; b=sVUaPld/6dT5e7Qzx4X52/oo4ZEsvE2IMq5nY/6tqqdmN93/qhcQQ61Gyrc6M4NYfz 3HrB75Kymb+K2N3mookJUqb1wPcP8yIpodyKkhEiv6Ar8cTtjXEtXAAjRbSn8FcdGHpK EtjexZJ2XGqqHFf585cIMxhO8YMEZZaLueTKSl/TqxQBGQt2/asHtYf28q7VzV4hW8/e Lfmbewqh8Bwn60E9Fzzfw0wojAoytVjLtMpwIbkurFtD5d0dbWzqvzpWOPHxgdyHbUJJ Bagxi0fTxVgqVfVOWiI6925/o7tS4ggv7x09LdbxkhjeB2Mqifrx6ICq+WK7CX8NgFyc fzzQ== X-Gm-Message-State: AOAM5323oLxBEOYUdO/Uw6gjw3MSynlhl4idyN2quCnCJ8Bh/gzmWYBr gJRlXQSz+8LkJ39jTwXZLNO6SQ== X-Google-Smtp-Source: ABdhPJytryBwKdTfdv8G9wIlxQA+n9LtZmSgH8yZNG/WYWUuLtc7P5j91jqQwsCp1BNbvmkx5NrmJA== X-Received: by 2002:a17:902:bc82:b0:148:eb68:f6dd with SMTP id bb2-20020a170902bc8200b00148eb68f6ddmr15339136plb.98.1643045216267; Mon, 24 Jan 2022 09:26:56 -0800 (PST) Received: from localhost.localdomain ([50.39.160.154]) by smtp.gmail.com with ESMTPSA id pc7sm15194530pjb.0.2022.01.24.09.26.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Jan 2022 09:26:55 -0800 (PST) From: Tadeusz Struk To: pbonzini@redhat.com Cc: Tadeusz Struk , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , kvm@vger.kernel.org, stable@vger.kernel.org, syzbot+6cde2282daa792c49ab8@syzkaller.appspotmail.com Subject: [PATCH RESEND] KVM: x86/mmu: fix UAF in paging_update_accessed_dirty_bits Date: Mon, 24 Jan 2022 09:26:33 -0800 Message-Id: <20220124172633.103323-1-tadeusz.struk@linaro.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Syzbot reported an use-after-free bug in update_accessed_dirty_bits(). Fix this by checking if the memremap'ed pointer is still valid. Cc: Paolo Bonzini Cc: Sean Christopherson Cc: Vitaly Kuznetsov Cc: Wanpeng Li Cc: Jim Mattson Cc: Joerg Roedel Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: kvm@vger.kernel.org Cc: Fixes: bd53cb35a3e9 ("X86/KVM: Handle PFNs outside of kernel reach when touching GPTEs") Link: https://syzkaller.appspot.com/bug?id=6cb6102a0a7b0c52060753dd62d070a1d1e71347 Reported-by: syzbot+6cde2282daa792c49ab8@syzkaller.appspotmail.com Signed-off-by: Tadeusz Struk --- arch/x86/kvm/mmu/paging_tmpl.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index 5b5bdac97c7b..d25b72d7b1b1 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -174,7 +174,7 @@ static int FNAME(cmpxchg_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, pfn = ((vaddr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; paddr = pfn << PAGE_SHIFT; table = memremap(paddr, PAGE_SIZE, MEMREMAP_WB); - if (!table) { + if (!table || !access_ok(table, PAGE_SIZE)) { mmap_read_unlock(current->mm); return -EFAULT; }