linux-ext4 - Re: [PATCH] libext2fs: write only core inode in update

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 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

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

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

Date:	Wed, 17 Jun 2009 18:46:42 -0400
From:	Theodore Tso <tytso@....edu>
To:	number9652 <number9652@...oo.com>
Cc:	Eric Sandeen <sandeen@...hat.com>,
	ext4 development <linux-ext4@...r.kernel.org>
Subject: Re: [PATCH] libext2fs: write only core inode in update_path()

On Wed, Jun 17, 2009 at 02:32:18PM -0700, number9652 wrote:
> I was too general in my statement above about what it broke.  I think (didn't test) if a program follows this path:
> extent_open(...,*handle)
> write_inode_full(...,handle->inode,...)
>   that it will read uninitialized memory in write_inode_full.  It
>seems clear that all previously written code assumes that this path
>is valid, and fixing all that to not assume that would seemingly be
>much more than just what your patch fixes and require more time to
>test.  If you only use read/write_inode_full, everything is still
>okay.

Um, but that can't happen; the ext2_extent_handle_t type is an opaque
type.  So outside of code in lib/ext2fs/extent.c, no one else can see
the inode in the ext2_handle_t.

The safest thing to do is to simply make the extent code only use
ext2_write_inode and ext2_read_inode.  Otherwise, we have to worry
about a user passing in the smaller 128-byte inode form.  The extent
code doesn't need any of the extended inode fields, so this is
completely safe.

						- Ted
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html