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=-8.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 8F4D1C4360F for ; Sat, 30 Mar 2019 05:43:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5605E218AE for ; Sat, 30 Mar 2019 05:43:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553924596; bh=ebyU1xh/LAWXwMIwVYqVq1jdrJRLGm7c+F3dlI/CX8M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=UNy2kCKmhQLnU4RfuX2zgs2Y/8TN6wKRTc3SUMPV5lxmMLstAIkk5bP8fJfkQLQg0 5yf+7aHScgY6V9073kf2o6tGncIudjJxoNVi5i0ORZ3w7riq/9aOdq/BH5HKA/hAJM bxXOQ2lWppq/IycqQJpwPtGY0uqXBYDofAONwPVM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730346AbfC3FnP (ORCPT ); Sat, 30 Mar 2019 01:43:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:38084 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726434AbfC3FnP (ORCPT ); Sat, 30 Mar 2019 01:43:15 -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 ECAA2218AC; Sat, 30 Mar 2019 05:43:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553924594; bh=ebyU1xh/LAWXwMIwVYqVq1jdrJRLGm7c+F3dlI/CX8M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=K7WYJONPEV/GhFY9G4mAt2pCMc9p24gDGy9uEJVLWFMiUp34PcVRPSo3bmqsmjncr gM2VcnDhO6ucND9ZhoiQ15p1cf/2p2JLJ5QxGB/4fKmQqK/R+Dq72G19wbq4wzQ/Dm FqylzNDd5aA/fNLEOLz/qVgHd+8+lTLto4/pHSN8= Date: Sat, 30 Mar 2019 06:43:11 +0100 From: Greg Kroah-Hartman To: Sasha Levin Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux-block@vger.kernel.org Subject: Re: [PATCH AUTOSEL 4.19 33/57] blk-mq: protect debugfs_create_files() from failures Message-ID: <20190330054311.GA23655@kroah.com> References: <20190330012854.32212-1-sashal@kernel.org> <20190330012854.32212-33-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190330012854.32212-33-sashal@kernel.org> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Fri, Mar 29, 2019 at 09:28:26PM -0400, Sasha Levin wrote: > 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 cb1e6cf7ac48..9dc3a0896462 100644 > --- a/block/blk-mq-debugfs.c > +++ b/block/blk-mq-debugfs.c > @@ -806,6 +806,9 @@ 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 > This was a 5.0-only thing, no need for it to be backported anywhere. Please drop it from all of your trees. thanks, greg k-h