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=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 7AE24C43381 for ; Thu, 28 Feb 2019 15:30:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 31C2120C01 for ; Thu, 28 Feb 2019 15:30:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551367826; bh=pLV/v2lvF82r6/IdQ8/R2cT6HYFG1XDstLvWJ6mdoI4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uI7DvTK8EXVLl7UepmKy4aLagkTK2BKbOJMb4tvMxTqbPz5RVPzk8sE3aWNiwV3bY KM43YWMUCpBVJwByy/IDG77Z+ssVVBEfHe/qCxnKsamc0cS9vxTOPNfEKeWI3Uj9Uy ycihBqF0+QAuzPYvbsMSX4B20RApOuHrlMRp83K0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387551AbfB1PJ1 (ORCPT ); Thu, 28 Feb 2019 10:09:27 -0500 Received: from mail.kernel.org ([198.145.29.99]:41974 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731575AbfB1PJX (ORCPT ); Thu, 28 Feb 2019 10:09:23 -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 D60D6218C3; Thu, 28 Feb 2019 15:09:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551366562; bh=pLV/v2lvF82r6/IdQ8/R2cT6HYFG1XDstLvWJ6mdoI4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EmfNuvZwyRztJFVZkTvRjr7bNFYyhTwWVa4jx6JrQQKdgZjdfbD5R3tTxwym5auvF FbR5hbpv9B7gJFkHCDxsTPhl9iGS16e9JHbZQYLUg1sCQnzPV1iWtMpOySPVTVJ0hI rUSI4DHrFP7kdp/1DzeV3tdMjm5qNbfLkwKBjLcQ= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Sasha Levin , linux-block@vger.kernel.org Subject: [PATCH AUTOSEL 4.20 43/81] blk-mq: protect debugfs_create_files() from failures Date: Thu, 28 Feb 2019 10:07:35 -0500 Message-Id: <20190228150813.10256-43-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190228150813.10256-1-sashal@kernel.org> References: <20190228150813.10256-1-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: Greg Kroah-Hartman [ Upstream commit 36991ca68db9dd43bac7f3519f080ee3939263ef ] If debugfs were to return a non-NULL error for a debugfs call, using that pointer later in debugfs_create_files() would crash. Fix that by properly checking the pointer before referencing it. Reported-by: Michal Hocko Reported-and-tested-by: syzbot+b382ba6a802a3d242790@syzkaller.appspotmail.com Reported-by: Tetsuo Handa Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- block/blk-mq-debugfs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index 10b284a1f18d7..ecdc6f07a37cd 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -812,6 +812,9 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = { static bool debugfs_create_files(struct dentry *parent, void *data, const struct blk_mq_debugfs_attr *attr) { + if (IS_ERR_OR_NULL(parent)) + return false; + d_inode(parent)->i_private = data; for (; attr->name; attr++) { -- 2.19.1