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Message-ID: <460D8435.3060503@pobox.com>
Date: Fri, 30 Mar 2007 17:42:13 -0400
From: Mark Lord <mlord@...ox.com>
To: Greg KH <gregkh@...e.de>
Cc: linux-kernel@...r.kernel.org, stable@...nel.org,
Justin Forbes <jmforbes@...uxtx.org>,
Zwane Mwaikambo <zwane@....linux.org.uk>,
Theodore Ts'o <tytso@....edu>,
Randy Dunlap <rdunlap@...otime.net>,
Dave Jones <davej@...hat.com>,
Chuck Wolber <chuckw@...ntumlinux.com>,
Chris Wedgwood <reviews@...cw.f00f.org>,
Michael Krufky <mkrufky@...uxtv.org>,
Chuck Ebbert <cebbert@...hat.com>,
torvalds@...ux-foundation.org, akpm@...ux-foundation.org,
alan@...rguk.ukuu.org.uk, Jeff Garzik <jeff@...zik.org>
Subject: Re: [patch 34/37] libata bugfix: HDIO_DRIVE_TASK
Greg KH wrote:
> -stable review patch. If anyone has any objections, please let us know.
>
> ------------------
> From: Mark Lord <liml@....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@...ox.com>
> Cc: Chuck Ebbert <cebbert@...hat.com>
> Signed-off-by: Jeff Garzik <jeff@...zik.org>
> Signed-off-by: Greg Kroah-Hartman <gregkh@...e.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@...ox.com>
---
drivers/ata/libata-scsi.c | 1 +
1 file changed, 1 insertion(+)
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -295,6 +295,7 @@ int ata_task_ioctl(struct scsi_device *s
scsi_cmd[8] = args[3];
scsi_cmd[10] = args[4];
scsi_cmd[12] = args[5];
+ scsi_cmd[13] = args[6] & 0x4f;
scsi_cmd[14] = args[0];
/* Good values for timeout and retries? Values below
--
Mark Lord
Real-Time Remedies Inc.
mlord@...ox.com
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