2017-07-07 08:56:53

by Johannes Thumshirn

Subject: [PATCH v2] scsi: sg: fix SG_DXFER_FROM_DEV transfers

SG_DXFER_FROM_DEV transfers do not necessarily have a dxferp as we set
it to NULL for the old sg_io read/write interface, but must have a length
bigger than 0. This fixes a regression introduced by commit 28676d869bbb
("scsi: sg: check for valid direction before starting the request")

Signed-off-by: Johannes Thumshirn <[email protected]>
Fixes: 28676d869bbb ("scsi: sg: check for valid direction before starting the request")
Reported-by: Chris Clayton <[email protected]>
Tested-by: Chris Clayton <[email protected]>
Cc: Douglas Gilbert <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
---
Changes to v1:
* Fix breakage of the sg_io v3 interface, verified using sg_inq

drivers/scsi/sg.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 21225d62b0c1..1e82d4128a84 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -758,8 +758,11 @@ static bool sg_is_valid_dxfer(sg_io_hdr_t *hp)
if (hp->dxferp || hp->dxfer_len > 0)
return false;
return true;
- case SG_DXFER_TO_DEV:
case SG_DXFER_FROM_DEV:
+ if (hp->dxfer_len < 0)
+ return false;
+ return true;
+ case SG_DXFER_TO_DEV:
case SG_DXFER_TO_FROM_DEV:
if (!hp->dxferp || hp->dxfer_len == 0)
return false;
--
2.12.3

2017-07-07 18:01:52

by Chris Clayton

Subject: Re: [PATCH v2] scsi: sg: fix SG_DXFER_FROM_DEV transfers

On 07/07/17 09:56, Johannes Thumshirn wrote:
> SG_DXFER_FROM_DEV transfers do not necessarily have a dxferp as we set
> it to NULL for the old sg_io read/write interface, but must have a length
> bigger than 0. This fixes a regression introduced by commit 28676d869bbb
> ("scsi: sg: check for valid direction before starting the request")
>

I've tested this new patch and the Nero applications can still find the optical drives on my laptop.

Tested-by: Chris Clayton <[email protected]>

> Signed-off-by: Johannes Thumshirn <[email protected]>
> Fixes: 28676d869bbb ("scsi: sg: check for valid direction before starting the request")
> Reported-by: Chris Clayton <[email protected]>
> Tested-by: Chris Clayton <[email protected]>
> Cc: Douglas Gilbert <[email protected]>
> Reviewed-by: Hannes Reinecke <[email protected]>
> ---
> Changes to v1:
> * Fix breakage of the sg_io v3 interface, verified using sg_inq
>
> drivers/scsi/sg.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
> index 21225d62b0c1..1e82d4128a84 100644
> --- a/drivers/scsi/sg.c
> +++ b/drivers/scsi/sg.c
> @@ -758,8 +758,11 @@ static bool sg_is_valid_dxfer(sg_io_hdr_t *hp)
> if (hp->dxferp || hp->dxfer_len > 0)
> return false;
> return true;
> - case SG_DXFER_TO_DEV:
> case SG_DXFER_FROM_DEV:
> + if (hp->dxfer_len < 0)
> + return false;
> + return true;
> + case SG_DXFER_TO_DEV:
> case SG_DXFER_TO_FROM_DEV:
> if (!hp->dxferp || hp->dxfer_len == 0)
> return false;
>

2017-07-11 19:05:49

by Douglas Gilbert

Subject: Re: [PATCH v2] scsi: sg: fix SG_DXFER_FROM_DEV transfers

On 2017-07-07 04:56 AM, Johannes Thumshirn wrote:
> SG_DXFER_FROM_DEV transfers do not necessarily have a dxferp as we set
> it to NULL for the old sg_io read/write interface, but must have a length
> bigger than 0. This fixes a regression introduced by commit 28676d869bbb
> ("scsi: sg: check for valid direction before starting the request")
>
> Signed-off-by: Johannes Thumshirn <[email protected]>
> Fixes: 28676d869bbb ("scsi: sg: check for valid direction before starting the request")
> Reported-by: Chris Clayton <[email protected]>
> Tested-by: Chris Clayton <[email protected]>
> Cc: Douglas Gilbert <[email protected]>
> Reviewed-by: Hannes Reinecke <[email protected]>

Acked-by: Douglas Gilbert <[email protected]>

> ---
> Changes to v1:
> * Fix breakage of the sg_io v3 interface, verified using sg_inq
>
> drivers/scsi/sg.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
> index 21225d62b0c1..1e82d4128a84 100644
> --- a/drivers/scsi/sg.c
> +++ b/drivers/scsi/sg.c
> @@ -758,8 +758,11 @@ static bool sg_is_valid_dxfer(sg_io_hdr_t *hp)
> if (hp->dxferp || hp->dxfer_len > 0)
> return false;
> return true;
> - case SG_DXFER_TO_DEV:
> case SG_DXFER_FROM_DEV:
> + if (hp->dxfer_len < 0)
> + return false;
> + return true;
> + case SG_DXFER_TO_DEV:
> case SG_DXFER_TO_FROM_DEV:
> if (!hp->dxferp || hp->dxfer_len == 0)
> return false;
>

2017-07-12 21:18:11

by Martin K. Petersen

Subject: Re: [PATCH v2] scsi: sg: fix SG_DXFER_FROM_DEV transfers

Johannes,

> SG_DXFER_FROM_DEV transfers do not necessarily have a dxferp as we set
> it to NULL for the old sg_io read/write interface, but must have a
> length bigger than 0. This fixes a regression introduced by commit
> 28676d869bbb ("scsi: sg: check for valid direction before starting the
> request")

Applied to 4.13/scsi-fixes. Thank you!

--
Martin K. Petersen Oracle Linux Engineering