From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([198.137.202.9]:60504 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S938665AbdAIPkS (ORCPT ); Mon, 9 Jan 2017 10:40:18 -0500 From: Christoph Hellwig Subject: [PATCH 25/32] xfs: don't allow di_size with high bit set Date: Mon, 9 Jan 2017 16:38:56 +0100 Message-Id: <1483976343-661-26-git-send-email-hch@lst.de> In-Reply-To: <1483976343-661-1-git-send-email-hch@lst.de> References: <1483976343-661-1-git-send-email-hch@lst.de> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: stable@vger.kernel.org Cc: linux-xfs@vger.kernel.org, "Darrick J. Wong" , Dave Chinner From: "Darrick J. Wong" commit ef388e2054feedaeb05399ed654bdb06f385d294 upstream. The on-disk field di_size is used to set i_size, which is a signed integer of loff_t. If the high bit of di_size is set, we'll end up with a negative i_size, which will cause all sorts of problems. Since the VFS won't let us create a file with such length, we should catch them here in the verifier too. Signed-off-by: Darrick J. Wong Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner --- fs/xfs/libxfs/xfs_inode_buf.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c index 134424f..c906e50 100644 --- a/fs/xfs/libxfs/xfs_inode_buf.c +++ b/fs/xfs/libxfs/xfs_inode_buf.c @@ -392,6 +392,14 @@ xfs_dinode_verify( if (dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC)) return false; + /* don't allow invalid i_size */ + if (be64_to_cpu(dip->di_size) & (1ULL << 63)) + return false; + + /* No zero-length symlinks. */ + if (S_ISLNK(be16_to_cpu(dip->di_mode)) && dip->di_size == 0) + return false; + /* only version 3 or greater inodes are extensively verified here */ if (dip->di_version < 3) return true; -- 2.1.4