From patchwork Tue May 26 18:52:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 225384 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EDC49C433E1 for ; Tue, 26 May 2020 19:04:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CF4FC2086A for ; Tue, 26 May 2020 19:04:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590519849; bh=iOAwMRBSlHy9XiMQy0/QkkEIEB2ri9V80CPULmrxMVo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ed+l9EQVqAGkGfCgmcTyXP+MozcerFBFzcgP451qBzq4knhmDtwI6u9eelPU2B4JG pif3tix+oxY/oexDmuG9G+eT5gYcYlOKnxEVUZNgvqvHIbmOvJeVhKuwWgdFz8ZomM OiAEwygTJP33iCXmy1uPSiiai+O0+suhxFkUY8Lo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391325AbgEZTEH (ORCPT ); Tue, 26 May 2020 15:04:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:59594 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391321AbgEZTEG (ORCPT ); Tue, 26 May 2020 15:04:06 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DA3C6208B3; Tue, 26 May 2020 19:04:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590519845; bh=iOAwMRBSlHy9XiMQy0/QkkEIEB2ri9V80CPULmrxMVo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uygF6mnmu44+2LXYNRceyW+TN36NBtQTgyvjz0SOBjvv77JxjDDUDg7jDJ9VzW1zQ 6118+ll/58SGgEifAKaHw5Jhhx49jrBkeliDy9wkg/PXPVLrieXxfXPfJb0Oni8nFZ Epiap2+T8yvheLW5zodJnSntRk5XEYpO9Lb8rDEU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexander Monakov , Joerg Roedel , iommu@lists.linux-foundation.org, Joerg Roedel , Sasha Levin Subject: [PATCH 4.19 12/81] iommu/amd: Fix over-read of ACPI UID from IVRS table Date: Tue, 26 May 2020 20:52:47 +0200 Message-Id: <20200526183927.467526457@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200526183923.108515292@linuxfoundation.org> References: <20200526183923.108515292@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alexander Monakov [ Upstream commit e461b8c991b9202b007ea2059d953e264240b0c9 ] IVRS parsing code always tries to read 255 bytes from memory when retrieving ACPI device path, and makes an assumption that firmware provides a zero-terminated string. Both of those are bugs: the entry is likely to be shorter than 255 bytes, and zero-termination is not guaranteed. With Acer SF314-42 firmware these issues manifest visibly in dmesg: AMD-Vi: ivrs, add hid:AMDI0020, uid:\_SB.FUR0\xf0\xa5, rdevid:160 AMD-Vi: ivrs, add hid:AMDI0020, uid:\_SB.FUR1\xf0\xa5, rdevid:160 AMD-Vi: ivrs, add hid:AMDI0020, uid:\_SB.FUR2\xf0\xa5, rdevid:160 AMD-Vi: ivrs, add hid:AMDI0020, uid:\_SB.FUR3>\x83e\x8d\x9a\xd1... The first three lines show how the code over-reads adjacent table entries into the UID, and in the last line it even reads garbage data beyond the end of the IVRS table itself. Since each entry has the length of the UID (uidl member of ivhd_entry struct), use that for memcpy, and manually add a zero terminator. Avoid zero-filling hid and uid arrays up front, and instead ensure the uid array is always zero-terminated. No change needed for the hid array, as it was already properly zero-terminated. Fixes: 2a0cb4e2d423c ("iommu/amd: Add new map for storing IVHD dev entry type HID") Signed-off-by: Alexander Monakov Cc: Joerg Roedel Cc: iommu@lists.linux-foundation.org Link: https://lore.kernel.org/r/20200511102352.1831-1-amonakov@ispras.ru Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin --- drivers/iommu/amd_iommu_init.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c index 2557ed112bc2..c7d0bb3b4a30 100644 --- a/drivers/iommu/amd_iommu_init.c +++ b/drivers/iommu/amd_iommu_init.c @@ -1334,8 +1334,8 @@ static int __init init_iommu_from_acpi(struct amd_iommu *iommu, } case IVHD_DEV_ACPI_HID: { u16 devid; - u8 hid[ACPIHID_HID_LEN] = {0}; - u8 uid[ACPIHID_UID_LEN] = {0}; + u8 hid[ACPIHID_HID_LEN]; + u8 uid[ACPIHID_UID_LEN]; int ret; if (h->type != 0x40) { @@ -1352,6 +1352,7 @@ static int __init init_iommu_from_acpi(struct amd_iommu *iommu, break; } + uid[0] = '\0'; switch (e->uidf) { case UID_NOT_PRESENT: @@ -1366,8 +1367,8 @@ static int __init init_iommu_from_acpi(struct amd_iommu *iommu, break; case UID_IS_CHARACTER: - memcpy(uid, (u8 *)(&e->uid), ACPIHID_UID_LEN - 1); - uid[ACPIHID_UID_LEN - 1] = '\0'; + memcpy(uid, &e->uid, e->uidl); + uid[e->uidl] = '\0'; break; default: