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=-19.4 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 3046CC636C9 for ; Thu, 15 Jul 2021 18:41:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 13110613D0 for ; Thu, 15 Jul 2021 18:41:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229506AbhGOSoM (ORCPT ); Thu, 15 Jul 2021 14:44:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:44292 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231425AbhGOSoK (ORCPT ); Thu, 15 Jul 2021 14:44:10 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7F29C613CA; Thu, 15 Jul 2021 18:41:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626374477; bh=DXNw3JdV5Xk7dzotIKYtcXxrIDggvEiE7eo5uR+1n8Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=F7TYzeaq2z92W1LWwvHGhG7IRXJjD4h94TUozSm0EDSg9MavY6RsSH1bC/KqHTPkJ 380sjtP/M/pfo9fak+7hzleSwNfnO/8kIgb565RDszu4glfIJuCFcciGm5jlUoSJYH mK1h5w1Rfl6DJbacR3GBfrmehMATpIRAq9V8Sbr4= 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 5.4 016/122] udf: Fix NULL pointer dereference in udf_symlink function Date: Thu, 15 Jul 2021 20:37:43 +0200 Message-Id: <20210715182453.506465950@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210715182448.393443551@linuxfoundation.org> References: <20210715182448.393443551@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 77b6d89b9bcd..3c3d3b20889c 100644 --- a/fs/udf/namei.c +++ b/fs/udf/namei.c @@ -933,6 +933,10 @@ 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