Re: [patch 34/37] libata bugfix: HDIO_DRIVE_TASK

Greg KH
2007-03-30T22:08:43Z

On Fri, Mar 30, 2007 at 05:42:13PM -0400, Mark Lord wrote:
> Greg KH wrote:
> >-stable review patch. If anyone has any objections, please let us know.
> >
> >------------------
> >From: Mark Lord <liml@rtr.ca>
> >
> >libata bugfix: HDIO_DRIVE_TASK
> >
> >I was trying to use HDIO_DRIVE_TASK for something today,
> >and discovered that the libata implementation does not copy
> >over the upper four LBA bits from args[6].
> >
> >This is serious, as any tools using this ioctl would have their
> >commands applied to the wrong sectors on the drive, possibly resulting
> >in disk corruption.
> >
> >Ideally, newer apps should use SG_IO/ATA_16 directly,
> >avoiding this bug. But with libata poised to displace drivers/ide,
> >better compatibility here is a must.
> >
> >This patch fixes libata to use the upper four LBA bits passed
> >in from the ioctl.
> >
> >The original drivers/ide implementation copies over all bits
> >except for the master/slave select bit. With this patch,
> >libata will copy only the four high-order LBA bits,
> >just in case there are assumptions elsewhere in libata (?).
> >
> >Signed-off-by: Mark Lord <mlord@pobox.com>
> >Cc: Chuck Ebbert <cebbert@redhat.com>
> >Signed-off-by: Jeff Garzik <jeff@garzik.org>
> >Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
> ..
>
> Mmmm.. I've just noticed another bit we should be preserving there,
> both for *stable* and current mainline.
>
> Instead of:
>
> >+ scsi_cmd[13] = args[6] & 0x0f;
>
> We should be doing:
>
> >+ scsi_cmd[13] = args[6] & 0x4f;
>
> As-is, the patch still helps, but it is not as useful as it could be.
> Here's the fixed version. I'm also sending out a 2.6.21 patch via Jeff.
>
> Signed-off-by: Mark Lord <mlord@pobox.com>

Can you forward that one to the stable@kernel.org address too, with the
full changelog and Jeff's ack/signed-off-by so that I will remember to
add it to the tree?

thanks,

greg k-h