2017-04-21 14:07:08

by Colin King

Subject: re: mtip32xx: add a status field to struct mtip_cmd

Hi,

CoverityScan found an issue with the following part of the patch:

- if (likely(!reserv))
- blk_mq_complete_request(rq, -ENODEV);
- else if (test_bit(MTIP_PF_IC_ACTIVE_BIT, &dd->port->flags)) {
+ if (likely(!reserv)) {
+ cmd->status = -ENODEV;
+ blk_mq_complete_request(rq, 0);
+ } else if (test_bit(MTIP_PF_IC_ACTIVE_BIT, &dd->port->flags)) {


The issue is:

static void mtip_no_dev_cleanup(struct request *rq, void *data, bool reserv)
{
struct driver_data *dd = (struct driver_data *)data;
struct mtip_cmd *cmd;

if (likely(!reserv)) {
cmd->status = -ENODEV;

CID 1430258 (#1 of 1): Uninitialized pointer write (UNINIT)4.
uninit_use: Using uninitialized value cmd.

..basically a null ptr dereference on cmd.

Colin

2017-04-21 14:15:21

by Jens Axboe

Subject: Re: mtip32xx: add a status field to struct mtip_cmd

On 04/21/2017 08:06 AM, Colin Ian King wrote:
> Hi,
>
> CoverityScan found an issue with the following part of the patch:
>
> - if (likely(!reserv))
> - blk_mq_complete_request(rq, -ENODEV);
> - else if (test_bit(MTIP_PF_IC_ACTIVE_BIT, &dd->port->flags)) {
> + if (likely(!reserv)) {
> + cmd->status = -ENODEV;
> + blk_mq_complete_request(rq, 0);
> + } else if (test_bit(MTIP_PF_IC_ACTIVE_BIT, &dd->port->flags)) {
>
>
From: Jens Axboe <[email protected]>
Subject: [PATCH] mtip32xx: fix dereference of stack garbage

We need to get the command payload from the request before
we attempt to dereference it.

Fixes: 4dda4735c581 ("mtip32xx: add a status field to struct mtip_cmd")
Signed-off-by: Jens Axboe <[email protected]>

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 66a6bd83faae..54c8736038de 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -4108,6 +4108,7 @@ static void mtip_no_dev_cleanup(struct request *rq, void *data, bool reserv)
struct mtip_cmd *cmd;

if (likely(!reserv)) {
+ cmd = blk_mq_rq_to_pdu(rq);
cmd->status = -ENODEV;
blk_mq_complete_request(rq);
} else if (test_bit(MTIP_PF_IC_ACTIVE_BIT, &dd->port->flags)) {

--
Jens Axboe

2017-04-21 14:38:04

by Christoph Hellwig

Subject: Re: mtip32xx: add a status field to struct mtip_cmd

On Fri, Apr 21, 2017 at 08:14:03AM -0600, Jens Axboe wrote:
> From: Jens Axboe <[email protected]>
> Subject: [PATCH] mtip32xx: fix dereference of stack garbage
>
> We need to get the command payload from the request before
> we attempt to dereference it.
>
> Fixes: 4dda4735c581 ("mtip32xx: add a status field to struct mtip_cmd")
> Signed-off-by: Jens Axboe <[email protected]>

Looks fine:

Reviewed-by: Christoph Hellwig <[email protected]>

2017-04-21 19:19:58

by Jens Axboe

Subject: Re: mtip32xx: add a status field to struct mtip_cmd

On 04/21/2017 08:37 AM, Christoph Hellwig wrote:
> On Fri, Apr 21, 2017 at 08:14:03AM -0600, Jens Axboe wrote:
>> From: Jens Axboe <[email protected]>
>> Subject: [PATCH] mtip32xx: fix dereference of stack garbage
>>
>> We need to get the command payload from the request before
>> we attempt to dereference it.
>>
>> Fixes: 4dda4735c581 ("mtip32xx: add a status field to struct mtip_cmd")
>> Signed-off-by: Jens Axboe <[email protected]>
>
> Looks fine:
>
> Reviewed-by: Christoph Hellwig <[email protected]>

Pushed, thanks.

--
Jens Axboe