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:	Thu, 2 Aug 2012 20:00:03 -0400
From:	Theodore Ts'o <tytso@....edu>
To:	Andreas Dilger <adilger@...mcloud.com>
Cc:	Ext4 Developers List <linux-ext4@...r.kernel.org>,
	"tony@...eyournoodle.com" <tony@...eyournoodle.com>
Subject: Re: [PATCH 7/7] libext2fs: enforce the block group descriptor size
 in ext2fs_open()

On Wed, Aug 01, 2012 at 01:45:32PM -0700, Andreas Dilger wrote:
> 
> I'm pretty sure that we've always checked that it is a power-of-two
> value. The problem with this change is that it makes it much harder
> to increase the size again in the future .

Unfortunately, no, there aren't any such checks anywhere in either the
kernel or e2fsck.  In fact, e2fsck wasn't checking s_desc_size at all
(although it was depending on it), which is what caused me to get very
worried...

> It would definitely need another feature flag, but it isn't clear
> without more investigation (that i can't do on my phone) if a COMPAT
> flag would be enough (which we would likely have anyway if we needed
> a larger descriptor) or if we need a more restrictive feature flag.

It seems very likely that any new feature that would require us to
expand the block group descriptor would require other changes to the
file system's structures that would require a more restrictive
feature flag....

						- 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

Powered by blists - more mailing lists