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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 EBB12C07E9D for ; Mon, 19 Jul 2021 15:01:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD7AC60FDC for ; Mon, 19 Jul 2021 15:01:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242697AbhGSOU3 (ORCPT ); Mon, 19 Jul 2021 10:20:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:53500 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242461AbhGSOTR (ORCPT ); Mon, 19 Jul 2021 10:19:17 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 62B9A6113E; Mon, 19 Jul 2021 14:59:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626706796; bh=A4QdYZ8oBR9zs9/MVrYuFTTY8xRdz18tMYVC1uI/r2A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pEZvHuXKuQIOhG8Fm9zi4h+tKQcgYxP/dg5IR7Maqaf2Mi5XkdKfSaSyPf9ILHG5g gY4tEs7LcLpMJ3txtWeCttZhUpABl1e+SL/bC0hRC6iYzSs9R63JidL91m7PRC2B9C LO9o1E/4bP88z/sZ8RDz4dDH/KLrPcrfl76YgioY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Arturo Giusti , Jan Kara , Sasha Levin Subject: [PATCH 4.4 102/188] udf: Fix NULL pointer dereference in udf_symlink function Date: Mon, 19 Jul 2021 16:51:26 +0200 Message-Id: <20210719144936.906637849@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144913.076563739@linuxfoundation.org> References: <20210719144913.076563739@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arturo Giusti [ Upstream commit fa236c2b2d4436d9f19ee4e5d5924e90ffd7bb43 ] In function udf_symlink, epos.bh is assigned with the value returned by udf_tgetblk. The function udf_tgetblk is defined in udf/misc.c and returns the value of sb_getblk function that could be NULL. Then, epos.bh is used without any check, causing a possible NULL pointer dereference when sb_getblk fails. This fix adds a check to validate the value of epos.bh. Link: https://bugzilla.kernel.org/show_bug.cgi?id=213083 Signed-off-by: Arturo Giusti Signed-off-by: Jan Kara Signed-off-by: Sasha Levin --- fs/udf/namei.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/udf/namei.c b/fs/udf/namei.c index f34c545f4e54..074560ad190e 100644 --- a/fs/udf/namei.c +++ b/fs/udf/namei.c @@ -945,6 +945,10 @@ static int udf_symlink(struct inode *dir, struct dentry *dentry, iinfo->i_location.partitionReferenceNum, 0); epos.bh = udf_tgetblk(sb, block); + if (unlikely(!epos.bh)) { + err = -ENOMEM; + goto out_no_entry; + } lock_buffer(epos.bh); memset(epos.bh->b_data, 0x00, bsize); set_buffer_uptodate(epos.bh); -- 2.30.2