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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 F2489C282CA for ; Wed, 13 Feb 2019 02:35:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B84D0222CC for ; Wed, 13 Feb 2019 02:35:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550025304; bh=EHKHFXrbKdK8wAs5O22yOtWYD1HLyR02FuxiFdINdw4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=bM7yE/TSBgdNyL/OByhMz9UhpHlJVKLctIJ6HjbL4UWpW/vAkjwjATejU7m6Eakwe f8mpde6FkFhID29jjBnn0UfMVeVf2bKJ94vrEJ0jQ9aRX4XRdUqiOM5zy4I1jMW1Gy g3XfbjTluHxxT2r43RHJObIy27EJOaxso1JNoYWI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387888AbfBMCfC (ORCPT ); Tue, 12 Feb 2019 21:35:02 -0500 Received: from mail.kernel.org ([198.145.29.99]:38540 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387855AbfBMCe5 (ORCPT ); Tue, 12 Feb 2019 21:34:57 -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 2906F222CE; Wed, 13 Feb 2019 02:34:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550025297; bh=EHKHFXrbKdK8wAs5O22yOtWYD1HLyR02FuxiFdINdw4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Q6CDgMYAvkPtbcmCQa3t6QLboqf66V3Vv4pHuZAybX2zi9tU+tqbCOaycBYiVUYPM oA9qQMJMDPjvzJzuXesRCCDx5MyzMtDgooip4G0KRIDyZ4PALAec7MySLaJ/o1WufZ vyIyCer0W6zFupnyvNeD1fFSNoyk/9QBtw2jYNiI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Tony Luck , Dan Williams , Sasha Levin , linux-nvdimm@lists.01.org, linux-acpi@vger.kernel.org Subject: [PATCH AUTOSEL 4.20 052/105] acpi/nfit: Fix race accessing memdev in nfit_get_smbios_id() Date: Tue, 12 Feb 2019 21:32:43 -0500 Message-Id: <20190213023336.19019-52-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190213023336.19019-1-sashal@kernel.org> References: <20190213023336.19019-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tony Luck [ 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 8535e7999769..2a2d7ec77252 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