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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B656EB64DC for ; Fri, 21 Jul 2023 16:12:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231500AbjGUQMl (ORCPT ); Fri, 21 Jul 2023 12:12:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39532 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231440AbjGUQMW (ORCPT ); Fri, 21 Jul 2023 12:12:22 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7FA6635A0 for ; Fri, 21 Jul 2023 09:11:59 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4C98C61D30 for ; Fri, 21 Jul 2023 16:11:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 856B6C433C8; Fri, 21 Jul 2023 16:11:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689955897; bh=c3DsV54k+3PaNxj9GZ+uBLu8LsynM9IfjBZ16qG3qHY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZY2b2gXWOx6xX5VNMy5K/90Cjfgn6auh1lIMveZBeLsNAQhsKkCZL/+to0RnMMkiu v61si9lZjNKIy3NTvP3EV6ehVnKOXs3OJxofuDoxEaKPejldQQkY/RnT6FVF/wwg9y zpblsZ4VoXgUhAhEaFB0jOTFRiOHSDd5THogBNgQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Andy Shevchenko , Armin Wolf , Hans de Goede , Sasha Levin Subject: [PATCH 6.4 068/292] platform/x86: wmi: Break possible infinite loop when parsing GUID Date: Fri, 21 Jul 2023 18:02:57 +0200 Message-ID: <20230721160531.711850645@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230721160528.800311148@linuxfoundation.org> References: <20230721160528.800311148@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Andy Shevchenko [ Upstream commit 028e6e204ace1f080cfeacd72c50397eb8ae8883 ] The while-loop may break on one of the two conditions, either ID string is empty or GUID matches. The second one, may never be reached if the parsed string is not correct GUID. In such a case the loop will never advance to check the next ID. Break possible infinite loop by factoring out guid_parse_and_compare() helper which may be moved to the generic header for everyone later on and preventing from similar mistake in the future. Interestingly that firstly it appeared when WMI was turned into a bus driver, but later when duplicated GUIDs were checked, the while-loop has been replaced by for-loop and hence no mistake made again. Fixes: a48e23385fcf ("platform/x86: wmi: add context pointer field to struct wmi_device_id") Fixes: 844af950da94 ("platform/x86: wmi: Turn WMI into a bus driver") Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20230621151155.78279-1-andriy.shevchenko@linux.intel.com Tested-by: Armin Wolf Reviewed-by: Hans de Goede Signed-off-by: Hans de Goede Signed-off-by: Sasha Levin --- drivers/platform/x86/wmi.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c index d81319a502efc..e1a3bfeeed529 100644 --- a/drivers/platform/x86/wmi.c +++ b/drivers/platform/x86/wmi.c @@ -136,6 +136,16 @@ static acpi_status find_guid(const char *guid_string, struct wmi_block **out) return AE_NOT_FOUND; } +static bool guid_parse_and_compare(const char *string, const guid_t *guid) +{ + guid_t guid_input; + + if (guid_parse(string, &guid_input)) + return false; + + return guid_equal(&guid_input, guid); +} + static const void *find_guid_context(struct wmi_block *wblock, struct wmi_driver *wdriver) { @@ -146,11 +156,7 @@ static const void *find_guid_context(struct wmi_block *wblock, return NULL; while (*id->guid_string) { - guid_t guid_input; - - if (guid_parse(id->guid_string, &guid_input)) - continue; - if (guid_equal(&wblock->gblock.guid, &guid_input)) + if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid)) return id->context; id++; } @@ -827,11 +833,7 @@ static int wmi_dev_match(struct device *dev, struct device_driver *driver) return 0; while (*id->guid_string) { - guid_t driver_guid; - - if (WARN_ON(guid_parse(id->guid_string, &driver_guid))) - continue; - if (guid_equal(&driver_guid, &wblock->gblock.guid)) + if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid)) return 1; id++; -- 2.39.2