From mboxrd@z Thu Jan 1 00:00:00 1970 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=DKIM_INVALID,DKIM_SIGNED, 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 59394C433E2 for ; Mon, 8 Jun 2020 23:14:09 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (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 2EBA221527 for ; Mon, 8 Jun 2020 23:14:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="kxiJfB+a" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2EBA221527 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id E4C1D22699; Mon, 8 Jun 2020 23:14:08 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 9HHjhItWdGZH; Mon, 8 Jun 2020 23:14:07 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by silver.osuosl.org (Postfix) with ESMTP id 25AA5204FB; Mon, 8 Jun 2020 23:14:07 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 04439C0863; Mon, 8 Jun 2020 23:14:07 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 609F4C016F for ; Mon, 8 Jun 2020 23:14:05 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 4A50086055 for ; Mon, 8 Jun 2020 23:14:05 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id WX1Dz9HyuC61 for ; Mon, 8 Jun 2020 23:14:04 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 731E585F29 for ; Mon, 8 Jun 2020 23:14:04 +0000 (UTC) Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (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 7027621534; Mon, 8 Jun 2020 23:14:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591658044; bh=ECHHm1tjjPiVV5BIUfnlAx1LvvWnDMygf0UXIqwcJhQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kxiJfB+aOzmDkY22060RMIx+9bC5XSiqscH6AYhC8gbIWVsetw0Rao8qv1pXQKxW3 DmF6rzk+ov0KbIZUfvDgOEk/nG4/UwrozNxdo2wx0JIjrnAz6igRvhQ52UILenXsZb Ue7ywNp4OtFqiIut8Lfi6Ut8KFiTUfSHv+3TfHs0= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 5.6 093/606] iommu/amd: Fix over-read of ACPI UID from IVRS table Date: Mon, 8 Jun 2020 19:03:38 -0400 Message-Id: <20200608231211.3363633-93-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200608231211.3363633-1-sashal@kernel.org> References: <20200608231211.3363633-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Cc: Sasha Levin , Alexander Monakov , iommu@lists.linux-foundation.org, Joerg Roedel X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" 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 2b9a67ecc6ac..5b81fd16f5fa 100644 --- a/drivers/iommu/amd_iommu_init.c +++ b/drivers/iommu/amd_iommu_init.c @@ -1329,8 +1329,8 @@ 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) { @@ -1347,6 +1347,7 @@ static int __init init_iommu_from_acpi(struct amd_iommu *iommu, break; } + uid[0] = '\0'; switch (e->uidf) { case UID_NOT_PRESENT: @@ -1361,8 +1362,8 @@ 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: -- 2.25.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu