linux-ext4 - Re: [PATCH] ext4: Fix ext4_empty_dir() for directories with holes

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 27 Nov 2019 14:44:15 -0500
From:   "Theodore Y. Ts'o" <tytso@....edu>
To:     Jan Kara <jack@...e.cz>
Cc:     linux-ext4@...r.kernel.org, stable@...r.kernel.org
Subject: Re: [PATCH] ext4: Fix ext4_empty_dir() for directories with holes

On Wed, Nov 27, 2019 at 02:12:58PM +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....

Hi Jan,

Thanks for the patch.

However, it looks like we're still vulnerable to the first block of
the directory being NULL?

> @@ -2833,19 +2833,25 @@ bool ext4_empty_dir(struct inode *inode)
>  		return true;
>  
>  	de = (struct ext4_dir_entry_2 *) bh->b_data;
                                         ^^^^^^^^^^^

						- Ted