From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933343AbdKATZt (ORCPT ); Wed, 1 Nov 2017 15:25:49 -0400 Received: from esa4.dell-outbound.iphmx.com ([68.232.149.214]:25846 "EHLO esa4.dell-outbound.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754586AbdKATZn (ORCPT ); Wed, 1 Nov 2017 15:25:43 -0400 X-LoopCount0: from 10.208.86.39 X-IronPort-AV: E=Sophos;i="5.44,330,1505797200"; d="scan'208";a="1172919506" X-DLP: DLP_GlobalPCIDSS From: Mario Limonciello To: dvhart@infradead.org, Andy Shevchenko Cc: LKML , platform-driver-x86@vger.kernel.org, Andy Lutomirski , quasisec@google.com, pali.rohar@gmail.com, rjw@rjwysocki.net, mjg59@google.com, hch@lst.de, Greg KH , Alan Cox , Mario Limonciello Subject: [PATCH v12 03/16] platform/x86: dell-wmi: increase severity of some failures Date: Wed, 1 Nov 2017 14:25:24 -0500 Message-Id: X-Mailer: git-send-email 2.7.4 In-Reply-To: References: In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There is a lot of error checking in place for the format of the WMI descriptor buffer, but some of the potentially raised issues should be considered critical failures. If the buffer size or header don't match, this is a good indication that the buffer format changed in a way that the rest of the data should not be relied upon. For the remaining data set vectors, continue to notate a warning in undefined results, but as those are fields that the descriptor intended to refer to other applications, don't fail if they're new values. Signed-off-by: Mario Limonciello Reviewed-by: Edward O'Callaghan Reviewed-by: Pali Rohár --- drivers/platform/x86/dell-wmi.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/platform/x86/dell-wmi.c b/drivers/platform/x86/dell-wmi.c index 1fbef560ca67..2cfaaa8faf0a 100644 --- a/drivers/platform/x86/dell-wmi.c +++ b/drivers/platform/x86/dell-wmi.c @@ -657,17 +657,18 @@ static int dell_wmi_check_descriptor_buffer(struct wmi_device *wdev) dev_err(&wdev->dev, "Dell descriptor buffer has invalid length (%d)\n", obj->buffer.length); - if (obj->buffer.length < 16) { - ret = -EINVAL; - goto out; - } + ret = -EINVAL; + goto out; } buffer = (u32 *)obj->buffer.pointer; - if (buffer[0] != 0x4C4C4544 && buffer[1] != 0x494D5720) - dev_warn(&wdev->dev, "Dell descriptor buffer has invalid signature (%*ph)\n", + if (buffer[0] != 0x4C4C4544 && buffer[1] != 0x494D5720) { + dev_err(&wdev->dev, "Dell descriptor buffer has invalid signature (%*ph)\n", 8, buffer); + ret = -EINVAL; + goto out; + } if (buffer[2] != 0 && buffer[2] != 1) dev_warn(&wdev->dev, "Dell descriptor buffer has unknown version (%d)\n", -- 2.14.1