2021-12-27 04:03:28

by Yue Haibing

Subject: [PATCH v2 -next] scsi: storvsc: Fix unsigned comparison to zero

The unsigned variable sg_count is being assigned a return value
from the call to scsi_dma_map() that can return -ENOMEM.

Fixes: 743b237c3a7b ("scsi: storvsc: Add Isolation VM support for storvsc driver")
Signed-off-by: YueHaibing <[email protected]>
---
v2: define sg_count as int type
---
drivers/scsi/storvsc_drv.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index ae293600d799..2273b843d9d2 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1753,7 +1753,6 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
struct hv_device *dev = host_dev->dev;
struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
struct scatterlist *sgl;
- unsigned int sg_count;
struct vmscsi_request *vm_srb;
struct vmbus_packet_mpb_array *payload;
u32 payload_sz;
@@ -1826,18 +1825,17 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);

sgl = (struct scatterlist *)scsi_sglist(scmnd);
- sg_count = scsi_sg_count(scmnd);

length = scsi_bufflen(scmnd);
payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
payload_sz = sizeof(cmd_request->mpb);

- if (sg_count) {
+ if (scsi_sg_count(scmnd)) {
unsigned long offset_in_hvpg = offset_in_hvpage(sgl->offset);
unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length);
struct scatterlist *sg;
unsigned long hvpfn, hvpfns_to_add;
- int j, i = 0;
+ int j, i = 0, sg_count;

if (hvpg_count > MAX_PAGE_BUFFER_COUNT) {

--
2.17.1

2021-12-28 18:04:19

by Michael Kelley (LINUX)

Subject: RE: [PATCH v2 -next] scsi: storvsc: Fix unsigned comparison to zero

From: YueHaibing <[email protected]> Sent: Sunday, December 26, 2021 8:03 PM
>
> The unsigned variable sg_count is being assigned a return value
> from the call to scsi_dma_map() that can return -ENOMEM.
>
> Fixes: 743b237c3a7b ("scsi: storvsc: Add Isolation VM support for storvsc driver")
> Signed-off-by: YueHaibing <[email protected]>
> ---
> v2: define sg_count as int type
> ---
> drivers/scsi/storvsc_drv.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
> index ae293600d799..2273b843d9d2 100644
> --- a/drivers/scsi/storvsc_drv.c
> +++ b/drivers/scsi/storvsc_drv.c
> @@ -1753,7 +1753,6 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
> struct hv_device *dev = host_dev->dev;
> struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
> struct scatterlist *sgl;
> - unsigned int sg_count;
> struct vmscsi_request *vm_srb;
> struct vmbus_packet_mpb_array *payload;
> u32 payload_sz;
> @@ -1826,18 +1825,17 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
> memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
>
> sgl = (struct scatterlist *)scsi_sglist(scmnd);
> - sg_count = scsi_sg_count(scmnd);
>
> length = scsi_bufflen(scmnd);
> payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
> payload_sz = sizeof(cmd_request->mpb);
>
> - if (sg_count) {
> + if (scsi_sg_count(scmnd)) {
> unsigned long offset_in_hvpg = offset_in_hvpage(sgl->offset);
> unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length);
> struct scatterlist *sg;
> unsigned long hvpfn, hvpfns_to_add;
> - int j, i = 0;
> + int j, i = 0, sg_count;
>
> if (hvpg_count > MAX_PAGE_BUFFER_COUNT) {
>
> --
> 2.17.1

Reviewed-by: Michael Kelley <[email protected]>

2022-01-05 05:41:49

by Martin K. Petersen

Subject: Re: [PATCH v2 -next] scsi: storvsc: Fix unsigned comparison to zero

YueHaibing,

> The unsigned variable sg_count is being assigned a return value
> from the call to scsi_dma_map() that can return -ENOMEM.
>
> Fixes: 743b237c3a7b ("scsi: storvsc: Add Isolation VM support for
> storvsc driver")

This should probably go through the Hyper-V tree - I presume that's
where the offending commit is sitting?

Otherwise I can take this after -rc1 is out.

--
Martin K. Petersen Oracle Linux Engineering

2022-01-05 12:23:51

by Wei Liu

Subject: Re: [PATCH v2 -next] scsi: storvsc: Fix unsigned comparison to zero

On Wed, Jan 05, 2022 at 12:41:31AM -0500, Martin K. Petersen wrote:
>
> YueHaibing,
>
> > The unsigned variable sg_count is being assigned a return value
> > from the call to scsi_dma_map() that can return -ENOMEM.
> >
> > Fixes: 743b237c3a7b ("scsi: storvsc: Add Isolation VM support for
> > storvsc driver")
>
> This should probably go through the Hyper-V tree - I presume that's
> where the offending commit is sitting?

Hi Martin

I will pick this up.

Thanks,
Wei.

>
> Otherwise I can take this after -rc1 is out.
>
> --
> Martin K. Petersen Oracle Linux Engineering