From patchwork Sat Mar 28 20:58:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 11463783 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AD9411392 for ; Sat, 28 Mar 2020 20:58:24 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 84A9020714 for ; Sat, 28 Mar 2020 20:58:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="nUdKSqSa"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="dh4KGrgz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 84A9020714 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=D/0k8h8OzHH0ecc4fdBWtqX9wuOEj7mj8wW29HTwDMk=; b=nUd KSqSaoCgd1yETjICH9XtIBK50vm6aFtKwt+4/RGnRnOW+B84Q8B8ajQeGh1w1FxkJR78Jl/F0lUdx vngT4iOQTxY41eUY2Jb2jXbMVx/FkNoLrz0p+AJt5N05/NNp2zOAeAldke5WCJvQ+l3/3E4Ywo2rH pAOzcprN2V2SdkBk1kSYForpRLTpR/XbHJ9HRE5twSMdk+JMZ2CSUwWICezYq5HNdN+aMpLDXMoMX x3eBbC3uzwG7nWj7TTp0JtKs2Sobsg9VWpe3fFPbHN9ci1BzwZL6OMgChGgC98G09S3GqchSBNLci DpnDjLDoDe/P9ga9s0hJ+rBG64BkBXg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jIIX5-0002C8-GC; Sat, 28 Mar 2020 20:58:19 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jIIX2-0002BU-HW for linux-arm-kernel@lists.infradead.org; Sat, 28 Mar 2020 20:58:18 +0000 Received: from e123331-lin.home (amontpellier-657-1-18-247.w109-210.abo.wanadoo.fr [109.210.65.247]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 471B320714; Sat, 28 Mar 2020 20:58:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585429095; bh=Wu4f1OnYj/QRZ0sdavFX0f/+cR088OEXn5AlxBMtMz8=; h=From:To:Cc:Subject:Date:From; b=dh4KGrgzdL5yTx1XuHjUoCMQJFxrBr+KcCzkDPyt1vPlYL3M29TnFZ96Q5Sg/wVH5 LzPspshFNInQYvUsLZXjDVL5VQtZf+nVMMjd75m/vlL4xmSoo/C6xLwqbzHAUmGg1u dl14tB6hykH/VhACWO/nxOm9f3endQrrFQCFRXYo= From: Ard Biesheuvel To: linux-arm-kernel@lists.infradead.org Subject: [PATCH] efi/libstub/arm64: avoid image_base value from efi_loaded_image Date: Sat, 28 Mar 2020 21:58:09 +0100 Message-Id: <20200328205809.23825-1-ardb@kernel.org> X-Mailer: git-send-email 2.17.1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200328_135816_602998_A40C4C8B X-CRM114-Status: GOOD ( 11.80 ) X-Spam-Score: -5.2 (-----) X-Spam-Report: SpamAssassin version 3.4.4 on bombadil.infradead.org summary: Content analysis details: (-5.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at https://www.dnswl.org/, high trust [198.145.29.99 listed in list.dnswl.org] 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.0 DKIMWL_WL_HIGH DKIMwl.org - Whitelisted High sender X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Boqun.Feng@microsoft.com, leif@nuviainc.com, linux-efi@vger.kernel.org, Ard Biesheuvel , mikelley@microsoft.com MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Commit 9f9223778ef3 ("efi/libstub/arm: Make efi_entry() an ordinary PE/COFF entrypoint") did some code refactoring to get rid of the EFI entry point assembler code, and in the process, it got rid of the assignment of image_addr to the value of _text. Instead, it switched to using the image_base field of the efi_loaded_image struct provided by UEFI, which should contain the same value. However, Michael reports that this is not the case: older GRUB builds corrupt this value in some way, and since we can easily switch back to referring to _text to discover this value, let's simply do that. While at it, fix another issue in commit 9f9223778ef3, which may result in the unassigned image_addr to be misidentified as the preferred load offset of the kernel, which is unlikely but will cause a boot crash if it does occur. Finally, let's add a warning if the _text vs. image_base discrepancy is detected, so we can tell more easily how widespread this issue actually is. Reported-by: Michael Kelley Signed-off-by: Ard Biesheuvel Tested-by: Michael Kelley --- drivers/firmware/efi/libstub/arm64-stub.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c index 9254cd8ab2d3..db0c1a9c1699 100644 --- a/drivers/firmware/efi/libstub/arm64-stub.c +++ b/drivers/firmware/efi/libstub/arm64-stub.c @@ -116,6 +116,7 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, * Mustang), we can still place the kernel at the address * 'dram_base + TEXT_OFFSET'. */ + *image_addr = (unsigned long)_text; if (*image_addr == preferred_offset) return EFI_SUCCESS; @@ -140,7 +141,11 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, } *image_addr = *reserve_addr + TEXT_OFFSET; } - memcpy((void *)*image_addr, image->image_base, kernel_size); + + if (image->image_base != _text) + pr_efi_err("FIRMWARE BUG: efi_loaded_image_t::image_base has bogus value\n"); + + memcpy((void *)*image_addr, _text, kernel_size); return EFI_SUCCESS; }