linux-kernel - Re: BUG? atleast >=2.6.19-rc5, x86 chroot on x86

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]

Message-ID: <26586.1165356671@redhat.com>
Date:	Tue, 05 Dec 2006 22:11:11 +0000
From:	David Howells <dhowells@...hat.com>
To:	Chuck Ebbert <76306.1226@...puserve.com>
Cc:	David Howells <dhowells@...hat.com>, vojtech@...e.cz, ak@....de,
	linux-kernel <linux-kernel@...r.kernel.org>,
	Kasper Sandberg <lkml@...anurb.dk>,
	Andrew Morton <akpm@...l.org>
Subject: Re: BUG? atleast >=2.6.19-rc5, x86 chroot on x86_64 

Chuck Ebbert <76306.1226@...puserve.com> wrote:

> I only have 32-bit userspace.  When I run your program against
> a directory on a JFS filesystem (msdos ioctls not supported)
> I get this on vanilla 2.6.19:

Can I just check?  You're using an x86_64 CPU in 64-bit mode with a 64-bit
kernel, but with a completely 32-bit userspace?

> I only have 32-bit userspace.  When I run your program against
> a directory on a JFS filesystem (msdos ioctls not supported)
> I get this on vanilla 2.6.19:

Wait!  You're using JFS, not VFAT?  Oh... I see.

Okay: It's not the MSDOS/VFAT patch that's wrong.  Please don't revert that.
It's the compat ioctl code that's "wrong".

So compat_sys_ioctl() used to return ENOTTY (ENOIOCTLCMD internally) because
the MSDOS ioctl was listed as one that could be translated but it didn't apply
to JFS.

But now, since all the block-based filesystem ioctls have been removed from
that list, you now get EINVAL, not ENOTTY.

> So apparently this is a feature?

Unfortunately, I think it has to be.  We could add a master list of ioctls to
be issued with particular errors if the driver doesn't support them, but is it
worth it?

A question for you: Why is userspace assuming that it'll get ENOTTY rather
than EINVAL?

David
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/