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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 817E2C43381 for ; Mon, 25 Feb 2019 21:31:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 46ACF21841 for ; Mon, 25 Feb 2019 21:31:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551130281; bh=0nTbpr+zA2IUbW9xHpt3KlpJBbmDBzpDwpcH3akLwUo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=er8qgoS1Bo9ZRUqWJirKni2TstJNMuMDGWOBLQP+KZ8YGc7fJKV/SXCqdG+XexaBV Rh7SHisuXbkAGV5gZDvrnCr+hdZVmbYsungdkO12+g+lWqVzGPShIaxn6skxYnn4fo Z2jtLjM5Ax0+uV6uAFoCLFSpL+1wVyWPSiG3WF9o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732287AbfBYVbU (ORCPT ); Mon, 25 Feb 2019 16:31:20 -0500 Received: from mail.kernel.org ([198.145.29.99]:36870 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729543AbfBYVbP (ORCPT ); Mon, 25 Feb 2019 16:31:15 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.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 73A5421841; Mon, 25 Feb 2019 21:31:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551130275; bh=0nTbpr+zA2IUbW9xHpt3KlpJBbmDBzpDwpcH3akLwUo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jDp/dQNVAyeKQfUq2U7ifaFckqRimDGKUgz+CDJIT6BcmcvHURw6qfdyRvd+asTbE N2tpnkT/DG2/hl1fuggsn8Fi5ahqxFkXiP+A2JsADWeL1yp0nJNxNykG6EFOsRQPFz zUChy7L3ml34Yv5AVjXy4Xvr5a12quGl0vIWiokI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jane Chu , Tony Luck , Dan Williams , Sasha Levin Subject: [PATCH 4.20 070/183] acpi/nfit: Fix race accessing memdev in nfit_get_smbios_id() Date: Mon, 25 Feb 2019 22:10:43 +0100 Message-Id: <20190225195106.285580384@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190225195054.748060397@linuxfoundation.org> References: <20190225195054.748060397@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 0919871ac37fdcf46c7657da0f1742efe096b399 ] Possible race accessing memdev structures after dropping the mutex. Dan Williams says this could race against another thread that is doing: # echo "ACPI0012:00" > /sys/bus/acpi/drivers/nfit/unbind Reported-by: Jane Chu Fixes: 23222f8f8dce ("acpi, nfit: Add function to look up nvdimm...") Signed-off-by: Tony Luck Signed-off-by: Dan Williams Signed-off-by: Sasha Levin --- drivers/acpi/nfit/core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 8535e7999769b..2a2d7ec772526 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -724,6 +724,7 @@ int nfit_get_smbios_id(u32 device_handle, u16 *flags) struct acpi_nfit_memory_map *memdev; struct acpi_nfit_desc *acpi_desc; struct nfit_mem *nfit_mem; + u16 physical_id; mutex_lock(&acpi_desc_lock); list_for_each_entry(acpi_desc, &acpi_descs, list) { @@ -731,10 +732,11 @@ int nfit_get_smbios_id(u32 device_handle, u16 *flags) list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) { memdev = __to_nfit_memdev(nfit_mem); if (memdev->device_handle == device_handle) { + *flags = memdev->flags; + physical_id = memdev->physical_id; mutex_unlock(&acpi_desc->init_mutex); mutex_unlock(&acpi_desc_lock); - *flags = memdev->flags; - return memdev->physical_id; + return physical_id; } } mutex_unlock(&acpi_desc->init_mutex); -- 2.19.1