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=-16.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,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 1E318C11F7F for ; Tue, 6 Jul 2021 12:02:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0C30D620DB for ; Tue, 6 Jul 2021 12:02:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243227AbhGFMDX (ORCPT ); Tue, 6 Jul 2021 08:03:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:47598 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237335AbhGFLgF (ORCPT ); Tue, 6 Jul 2021 07:36:05 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1D17561C43; Tue, 6 Jul 2021 11:26:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625570818; bh=p0CvNcx46PtI7/X7Q3EmGj6Fb+afv852J6xrIG0GXak=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=t6LPQuc3jZZOxOXt0kaK6v88Z0WdNBg8KnYvOQJnil6ouIco69AvCgejUH/NcKy1G q/1+fdbTTRvL2BH988uwQebXJxSg3QGrgIn69+XxNlZ+saDUxyfIHlvgX9udrWvN/j GGSj3DbgO466ZZUmmiGBTPOAtxwxR5XMAD+jrhdG2zcaLchxp3Jk4rB3uN8drKCuf9 O3fPa28SLOllgOp/j4HeCshzgK4c18tJjFLro2DYfz9oXdFxKJPC4ZgYLu04qlCBYd 9HqFFcwG1dsNt8XsyFTJvrHKaIRC8OKEecG4e0ERLTlpafoGn8nu3VarhAZ2fkY2q5 woHUMSOax+C6A== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Arturo Giusti , Jan Kara , Sasha Levin Subject: [PATCH AUTOSEL 4.19 15/55] udf: Fix NULL pointer dereference in udf_symlink function Date: Tue, 6 Jul 2021 07:25:58 -0400 Message-Id: <20210706112638.2065023-15-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210706112638.2065023-1-sashal@kernel.org> References: <20210706112638.2065023-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 58cc2414992b..9cfb555db1ad 100644 --- a/fs/udf/namei.c +++ b/fs/udf/namei.c @@ -948,6 +948,10 @@ 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