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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 EA070C282CE for ; Wed, 24 Apr 2019 17:51:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AEE50218B0 for ; Wed, 24 Apr 2019 17:51:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556128290; bh=rzs5XJUYSb8zmSaJNaz3E6Icm+WXTTSI3EwdVIPc5gI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=qRGhiPi/DKAqqmF30pN9xFI868t0VHxPD+vulIZZSfhAS+G6ZbO/gwoQx31SxP7ZO CgAXF6Apfu7vwj16gpREm2B6QoZFWugYeZ+v2A4zjNMEwL5QqZCEYFF1xMGjcknTu+ ZzvwENoiSun4P9+TTyAudqYMAVNgHViZ4Un+g65A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391426AbfDXRv3 (ORCPT ); Wed, 24 Apr 2019 13:51:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:54940 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390731AbfDXR2j (ORCPT ); Wed, 24 Apr 2019 13:28:39 -0400 Received: from localhost (62-193-50-229.as16211.net [62.193.50.229]) (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 2FC2221903; Wed, 24 Apr 2019 17:28:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556126918; bh=rzs5XJUYSb8zmSaJNaz3E6Icm+WXTTSI3EwdVIPc5gI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Oq7bhHqTh1jBNlKl/yXLOpNK9jUa9b6xmEg+ChF4vX7bYts7kx+JScGwlPIz1A7N3 XMT+McT9RWN0gS01nO/CmgaD/10IEdwxGVRXxQynCBZzJ8bSm1orjN8iga1PWivcJi I8e1PX5C65SNmBwjrUIgsskEji5MT20sHrxhBTgc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jann Horn , Michal Hocko , Tejun Heo Subject: [PATCH 4.14 62/70] device_cgroup: fix RCU imbalance in error case Date: Wed, 24 Apr 2019 19:10:22 +0200 Message-Id: <20190424170918.715478731@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190424170906.751869122@linuxfoundation.org> References: <20190424170906.751869122@linuxfoundation.org> User-Agent: quilt/0.66 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 From: Jann Horn commit 0fcc4c8c044e117ac126ab6df4138ea9a67fa2a9 upstream. When dev_exception_add() returns an error (due to a failed memory allocation), make sure that we move the RCU preemption count back to where it was before we were called. We dropped the RCU read lock inside the loop body, so we can't just "break". sparse complains about this, too: $ make -s C=2 security/device_cgroup.o ./include/linux/rcupdate.h:647:9: warning: context imbalance in 'propagate_exception' - unexpected unlock Fixes: d591fb56618f ("device_cgroup: simplify cgroup tree walk in propagate_exception()") Cc: stable@vger.kernel.org Signed-off-by: Jann Horn Acked-by: Michal Hocko Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- security/device_cgroup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/security/device_cgroup.c +++ b/security/device_cgroup.c @@ -569,7 +569,7 @@ static int propagate_exception(struct de devcg->behavior == DEVCG_DEFAULT_ALLOW) { rc = dev_exception_add(devcg, ex); if (rc) - break; + return rc; } else { /* * in the other possible cases: