From: "Theodore Y. Ts'o" <tytso@mit.edu>
To: Jan Kara <jack@suse.cz>
Cc: linux-ext4@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH 1/2] ext4: Fix ext4_empty_dir() for directories with holes
Date: Sun, 8 Dec 2019 19:12:11 -0500 [thread overview]
Message-ID: <20191209001211.GA9343@mit.edu> (raw)
In-Reply-To: <20191202170213.4761-2-jack@suse.cz>
On Mon, Dec 02, 2019 at 06:02:12PM +0100, Jan Kara wrote:
> Function ext4_empty_dir() doesn't correctly handle directories with
> holes and crashes on bh->b_data dereference when bh is NULL. Reorganize
> the loop to use 'offset' variable all the times instead of comparing
> pointers to current direntry with bh->b_data pointer. Also add more
> strict checking of '.' and '..' directory entries to avoid entering loop
> in possibly invalid state on corrupted filesystems.
>
> References: CVE-2019-19037
> CC: stable@vger.kernel.org
> Fixes: 4e19d6b65fb4 ("ext4: allow directory holes")
> Signed-off-by: Jan Kara <jack@suse.cz>
Applied, thanks.
- Ted
next prev parent reply other threads:[~2019-12-09 0:12 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-02 17:02 [PATCH 0/2 v2] ext4: Handle directories with holes better Jan Kara
2019-12-02 17:02 ` [PATCH 1/2] ext4: Fix ext4_empty_dir() for directories with holes Jan Kara
2019-12-09 0:12 ` Theodore Y. Ts'o [this message]
2019-12-02 17:02 ` [PATCH 2/2] ext4: Check for directory entries too close to block end Jan Kara
2019-12-09 0:42 ` Theodore Y. Ts'o
2019-12-09 0:43 ` [PATCH] ext4: optimize __ext4_check_dir_entry() Theodore Ts'o
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