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,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 790D6C282CE for ; Wed, 24 Apr 2019 17:33:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4AF9521903 for ; Wed, 24 Apr 2019 17:33:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556127183; bh=b+oR/mK6zwMUE6kxKjk4NmNv54U9v+ROyYUlUBBLufM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JAqSoCoztiOnN31EHO/0ldWbkMaaSjbdSebkww1+3zDlJIQA5Odc91oLzb0Ep4/nJ LSE55jaupArFolyIIjdQJi39bdLe4wTAyUriVU0sfAL1ntEoLvlkqsQBly9E2SFuaX Et+j1k/td4nrkkD8dalM0ygeP2ASF4QcQxyh3knY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391226AbfDXRdC (ORCPT ); Wed, 24 Apr 2019 13:33:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:59852 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390836AbfDXRdA (ORCPT ); Wed, 24 Apr 2019 13:33:00 -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 A1A5F21903; Wed, 24 Apr 2019 17:32:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556127180; bh=b+oR/mK6zwMUE6kxKjk4NmNv54U9v+ROyYUlUBBLufM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EVq4bfixzfphkRVrUR7fhK/xzW+xGeI1ItuHVCiH70ONubWohFPDYZGS8lVyw6576 uzDsX/uYsYdi0fjsWmQw9bTF160yrDf5e44tBmH8zmikzq3vO0aD3grChx9pmTLytl 4GFveqifQ3NKrJTJO5JqjMD7I6uwvpWpCn4286uI= 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 4.19 90/96] device_cgroup: fix RCU imbalance in error case Date: Wed, 24 Apr 2019 19:10:35 +0200 Message-Id: <20190424170925.909885307@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190424170919.829037226@linuxfoundation.org> References: <20190424170919.829037226@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 @@ -560,7 +560,7 @@ 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: