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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 E05C0C33CAF for ; Thu, 16 Jan 2020 18:23:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BCAA22051A for ; Thu, 16 Jan 2020 18:23:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579198997; bh=UT/9yJA7WLAXr38wzBDo6dD4fF4s8HfezFiBEZcbVJo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=fFk47fZgPgisTl1eAvlag8NScfjxm9E4kcnTCN9wLLRy+ymmf4CmdnpeM6/6Qbd9j fQBGCxX0E1OjWW/EkZOZHGADUoa+A1UCm4RKYy7afBmuW1oljYiC97cW8mZgYV/Uhe FfsHreDAzJwaoCX36clfXGZNqjTxJLBazsWmJuH0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2395538AbgAPSXJ (ORCPT ); Thu, 16 Jan 2020 13:23:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:37130 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392452AbgAPR1T (ORCPT ); Thu, 16 Jan 2020 12:27:19 -0500 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 C79F1246D4; Thu, 16 Jan 2020 17:27:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579195639; bh=UT/9yJA7WLAXr38wzBDo6dD4fF4s8HfezFiBEZcbVJo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QvPpsz6TUPwGlGkpBCy5L9SWncGjKQhNZtBmIvhwE8+n7SLtpzDJkGXjBePR4PgSX 79jrS71IEG1vIV5s7HFds1IqebdHbnly7S2ak88lEHbeL9IN8xQxC24sv2R/vSni3c JRb6he95dfMtrMWFphe0itOKcg8XhA74JrQTNbxo= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Robert Richter , Borislav Petkov , "linux-edac@vger.kernel.org" , James Morse , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH AUTOSEL 4.14 204/371] EDAC/mc: Fix edac_mc_find() in case no device is found Date: Thu, 16 Jan 2020 12:21:16 -0500 Message-Id: <20200116172403.18149-147-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116172403.18149-1-sashal@kernel.org> References: <20200116172403.18149-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-edac-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-edac@vger.kernel.org From: Robert Richter [ Upstream commit 29a0c843973bc385918158c6976e4dbe891df969 ] The function should return NULL in case no device is found, but it always returns the last checked mc device from the list even if the index did not match. Fix that. I did some analysis why this did not raise any issues for about 3 years and the reason is that edac_mc_find() is mostly used to search for existing devices. Thus, the bug is not triggered. [ bp: Drop the if (mci->mc_idx > idx) test in favor of readability. ] Fixes: c73e8833bec5 ("EDAC, mc: Fix locking around mc_devices list") Signed-off-by: Robert Richter Signed-off-by: Borislav Petkov Cc: "linux-edac@vger.kernel.org" Cc: James Morse Cc: Mauro Carvalho Chehab Link: https://lkml.kernel.org/r/20190514104838.15065-1-rrichter@marvell.com Signed-off-by: Sasha Levin --- drivers/edac/edac_mc.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c index f7fa05fee45a..329021189c38 100644 --- a/drivers/edac/edac_mc.c +++ b/drivers/edac/edac_mc.c @@ -680,22 +680,18 @@ static int del_mc_from_global_list(struct mem_ctl_info *mci) struct mem_ctl_info *edac_mc_find(int idx) { - struct mem_ctl_info *mci = NULL; + struct mem_ctl_info *mci; struct list_head *item; mutex_lock(&mem_ctls_mutex); list_for_each(item, &mc_devices) { mci = list_entry(item, struct mem_ctl_info, link); - - if (mci->mc_idx >= idx) { - if (mci->mc_idx == idx) { - goto unlock; - } - break; - } + if (mci->mc_idx == idx) + goto unlock; } + mci = NULL; unlock: mutex_unlock(&mem_ctls_mutex); return mci; -- 2.20.1