From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S940039AbdAJNxK (ORCPT ); Tue, 10 Jan 2017 08:53:10 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:34926 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S939982AbdAJNxF (ORCPT ); Tue, 10 Jan 2017 08:53:05 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , "Darrick J. Wong" , Dave Chinner , Dave Chinner , Christoph Hellwig Subject: [PATCH 4.9 195/206] xfs: dont crash if reading a directory results in an unexpected hole Date: Tue, 10 Jan 2017 14:37:58 +0100 Message-Id: <20170110131511.996527229@linuxfoundation.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170110131502.767555407@linuxfoundation.org> References: <20170110131502.767555407@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Darrick J. Wong" commit 96a3aefb8ffde23180130460b0b2407b328eb727 upstream. In xfs_dir3_data_read, we can encounter the situation where err == 0 and *bpp == NULL if the given bno offset happens to be a hole; this leads to a crash if we try to set the buffer type after the _da_read_buf call. Holes can happen due to corrupt or malicious entries in the bmbt data, so be a little more careful when we're handling buffers. Signed-off-by: Darrick J. Wong Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner Cc: Christoph Hellwig Signed-off-by: Greg Kroah-Hartman --- fs/xfs/libxfs/xfs_dir2_data.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/xfs/libxfs/xfs_dir2_data.c +++ b/fs/xfs/libxfs/xfs_dir2_data.c @@ -329,7 +329,7 @@ xfs_dir3_data_read( err = xfs_da_read_buf(tp, dp, bno, mapped_bno, bpp, XFS_DATA_FORK, &xfs_dir3_data_buf_ops); - if (!err && tp) + if (!err && tp && *bpp) xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_DATA_BUF); return err; }