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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 CDE9CC76186 for ; Wed, 24 Jul 2019 20:09:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A3AB320665 for ; Wed, 24 Jul 2019 20:09:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563998948; bh=TpOGltvQUnJRPxFY3KeVJnxJ/YWgGmP7oCbsg8kOBm0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Ik5sJaIVmHqcIDbATObx/T5xbCxW+VNMeB2FHzSaHsYl9z+21RVVRfXUBnlK9rWqI 8d2LRgpI1U17bztrGv50cyvxbDCXvNSosPReKtKt2NeYrrCaPHqjbIDorRHaOmQ7JD 6NWr0rUX11KCcZLrhVw+uRlf2o3XUTPSVH1vuso0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405325AbfGXUBD (ORCPT ); Wed, 24 Jul 2019 16:01:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:49472 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405317AbfGXUBC (ORCPT ); Wed, 24 Jul 2019 16:01:02 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.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 E9C69206BA; Wed, 24 Jul 2019 20:01:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563998461; bh=TpOGltvQUnJRPxFY3KeVJnxJ/YWgGmP7oCbsg8kOBm0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dPbwKkqLsBTV817q/e2bQiFdfcYVGSm4WY8xlqnRy40g9JVD1C/i6N6ncmSJdzzrk Lja/eXtbsV/TXm1yF/V5p8CNgOzI13ybsQu4PKnzqCCMHU9isSwccumnUn37GUED9q /La83ByLFTXGR3sdOtku2Gv6PuS3OcJiUj1Kp09U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nadav Amit , Andrew Morton , Dan Williams , Borislav Petkov , Toshi Kani , Peter Zijlstra , Dave Hansen , Bjorn Helgaas , Ingo Molnar , Linus Torvalds Subject: [PATCH 5.1 344/371] resource: fix locking in find_next_iomem_res() Date: Wed, 24 Jul 2019 21:21:36 +0200 Message-Id: <20190724191749.558873757@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190724191724.382593077@linuxfoundation.org> References: <20190724191724.382593077@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Nadav Amit commit 49f17c26c123b60fd1c74629eef077740d16ffc2 upstream. Since resources can be removed, locking should ensure that the resource is not removed while accessing it. However, find_next_iomem_res() does not hold the lock while copying the data of the resource. Keep holding the lock while the data is copied. While at it, change the return value to a more informative value. It is disregarded by the callers. [akpm@linux-foundation.org: fix find_next_iomem_res() documentation] Link: http://lkml.kernel.org/r/20190613045903.4922-2-namit@vmware.com Fixes: ff3cc952d3f00 ("resource: Add remove_resource interface") Signed-off-by: Nadav Amit Reviewed-by: Andrew Morton Reviewed-by: Dan Williams Cc: Borislav Petkov Cc: Toshi Kani Cc: Peter Zijlstra Cc: Dave Hansen Cc: Bjorn Helgaas Cc: Ingo Molnar Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- kernel/resource.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) --- a/kernel/resource.c +++ b/kernel/resource.c @@ -325,7 +325,7 @@ EXPORT_SYMBOL(release_resource); * * If a resource is found, returns 0 and @*res is overwritten with the part * of the resource that's within [@start..@end]; if none is found, returns - * -1 or -EINVAL for other invalid parameters. + * -ENODEV. Returns -EINVAL for invalid parameters. * * This function walks the whole tree and not just first level children * unless @first_lvl is true. @@ -364,16 +364,16 @@ static int find_next_iomem_res(resource_ break; } - read_unlock(&resource_lock); - if (!p) - return -1; + if (p) { + /* copy data */ + res->start = max(start, p->start); + res->end = min(end, p->end); + res->flags = p->flags; + res->desc = p->desc; + } - /* copy data */ - res->start = max(start, p->start); - res->end = min(end, p->end); - res->flags = p->flags; - res->desc = p->desc; - return 0; + read_unlock(&resource_lock); + return p ? 0 : -ENODEV; } static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,