From patchwork Tue Oct 15 18:18:02 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Grall X-Patchwork-Id: 176398 Delivered-To: patch@linaro.org Received: by 2002:a92:7e96:0:0:0:0:0 with SMTP id q22csp6269034ill; Tue, 15 Oct 2019 11:19:37 -0700 (PDT) X-Google-Smtp-Source: APXvYqz1gUgIBgogk/XnoQ23k/JhlzAGwy/cn4SRKLcuCH/Y4RSSWZ3fi1v2GyPlIev+BmtOUTza X-Received: by 2002:a92:9892:: with SMTP id a18mr7266765ill.189.1571163577761; Tue, 15 Oct 2019 11:19:37 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1571163577; cv=none; d=google.com; s=arc-20160816; b=UEZOIjT62oIJQPK0SKfgtQQL2R+5yb7PzpOjHmPk6+xi48wtd4Tn1bFNkcENj3j78v 6NYpYu4cRzr5aUOK5hbvDRULsl5iF8GcFzgeVcSOsW7O0QIJfznZvn0vudXXvIEMO8F4 0a+syrZJYEDBXzrHr0CsUiNmqDe4evssnxCDYePpbcZOFgJP3Fox8KTQgeB+eBnQUtdo 0P7GiPESBFpUzGgMQ+YvQJnY7fjYn2fw4sbgXla+LE0OYSWs+r+GKeOVi7XriId0VqU7 toU2a8c1Sl8UNn5IGzzPRuCGk6GVSQBUujEMnQ3GchRfiVMMazcqJVOaU65t3HGOW4X0 Ch8A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:content-transfer-encoding:mime-version:cc :list-subscribe:list-help:list-post:list-unsubscribe:list-id :precedence:subject:message-id:date:to:from; bh=I9wxIMgjGJeNtlZX2JWDxEIoQGkZqOyRpvd3fPbGu7E=; b=AvldRvsNIM7khPkh4jDxntl5A1b2U53tB/D3pKhQTjcNPovAtsB4ZKHRE9a04NVqhF 0C43FlX41r5X1vjY83maeKuhQXqXBRpizhQ9GqGqBWkgomkuUTw3JhyjKWJFtfI6AFk3 QneH/Fi5KCRC451/iyU/kkyl0FeVyXvJIU+DYJPPu7R+iCOpJk81MMaBGqGw9bNXKSzH LMvYAzEjRiCDWtU7JCgHH37cnI6XN8gUg4xCaL2SwapRLemXyW2v4vZEzLUTx+F4dh/L D7d5kkxxQKYKp4tNm+c6fDoiE+TF9e7iJngARGYlBsLweRBb5XqAhXldjCrpTWHOD6Le RHOA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of xen-devel-bounces@lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Return-Path: Received: from lists.xenproject.org (lists.xenproject.org. [192.237.175.120]) by mx.google.com with ESMTPS id 145si35148329jaa.71.2019.10.15.11.19.37 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 15 Oct 2019 11:19:37 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of xen-devel-bounces@lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of xen-devel-bounces@lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iKROf-0007Mi-Ho; Tue, 15 Oct 2019 18:18:13 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iKROe-0007Ma-D8 for xen-devel@lists.xenproject.org; Tue, 15 Oct 2019 18:18:12 +0000 X-Inumbo-ID: 251aff05-ef78-11e9-939d-12813bfff9fa Received: from foss.arm.com (unknown [217.140.110.172]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTP id 251aff05-ef78-11e9-939d-12813bfff9fa; Tue, 15 Oct 2019 18:18:11 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B221E28; Tue, 15 Oct 2019 11:18:10 -0700 (PDT) Received: from e108454-lin.cambridge.arm.com (e108454-lin.cambridge.arm.com [10.1.196.50]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0BDED3F6C4; Tue, 15 Oct 2019 11:18:08 -0700 (PDT) From: Julien Grall To: xen-devel@lists.xenproject.org Date: Tue, 15 Oct 2019 19:18:02 +0100 Message-Id: <20191015181802.21957-1-julien.grall@arm.com> X-Mailer: git-send-email 2.11.0 Subject: [Xen-devel] [PATCH for-4.13] xen/arm: Don't use _end in is_xen_fixed_mfn() X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: jgross@suse.com, Stefano Stabellini , Julien Grall , Wei Liu , Konrad Rzeszutek Wilk , George Dunlap , Andrew Cooper , Ian Jackson , Tim Deegan , Julien Grall , Jan Beulich , Volodymyr Babchuk MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" virt_to_maddr() is using the hardware page-table walk instructions to translate a virtual address to physical address. The function should only be called on virtual address mapped. _end points past the end of Xen binary and may not be mapped when the binary size is page-aligned. This means virt_to_maddr() will not be able to do the translation and therefore crash Xen. Note there is also an off-by-one issue in this code, but the panic will trump that. Both issues can be fixed by using _end - 1 in the check. Signed-off-by: Julien Grall --- Cc: Andrew Cooper Cc: George Dunlap Cc: Ian Jackson Cc: Jan Beulich Cc: Julien Grall Cc: Konrad Rzeszutek Wilk Cc: Stefano Stabellini Cc: Tim Deegan Cc: Wei Liu Cc: jgross@suse.com x86 seems to be affected by the off-by-one issue. Jan, Andrew? This could be reached by a domain via XEN_SYSCTL_page_offline_op. However, the operation is not security supported (see XSA-77). So we are fine here. --- xen/include/asm-arm/mm.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/xen/include/asm-arm/mm.h b/xen/include/asm-arm/mm.h index 262d92f18d..174acd8859 100644 --- a/xen/include/asm-arm/mm.h +++ b/xen/include/asm-arm/mm.h @@ -153,7 +153,7 @@ extern unsigned long xenheap_base_pdx; #define is_xen_fixed_mfn(mfn) \ ((mfn_to_maddr(mfn) >= virt_to_maddr(&_start)) && \ - (mfn_to_maddr(mfn) <= virt_to_maddr(&_end))) + (mfn_to_maddr(mfn) <= virt_to_maddr(_end - 1))) #define page_get_owner(_p) (_p)->v.inuse.domain #define page_set_owner(_p,_d) ((_p)->v.inuse.domain = (_d))