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* re: mtip32xx: add a status field to struct mtip_cmd
@ 2017-04-21 14:06 Colin Ian King
  2017-04-21 14:14 ` Jens Axboe
  0 siblings, 1 reply; 4+ messages in thread
From: Colin Ian King @ 2017-04-21 14:06 UTC (permalink / raw)
  To: Christoph Hellwig, Johannes Thumshirn, Jens Axboe; +Cc: linux-kernel

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

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: mtip32xx: add a status field to struct mtip_cmd
  2017-04-21 14:06 mtip32xx: add a status field to struct mtip_cmd Colin Ian King
@ 2017-04-21 14:14 ` Jens Axboe
  2017-04-21 14:37   ` Christoph Hellwig
  0 siblings, 1 reply; 4+ messages in thread
From: Jens Axboe @ 2017-04-21 14:14 UTC (permalink / raw)
  To: Colin Ian King, Christoph Hellwig, Johannes Thumshirn; +Cc: linux-kernel

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 <axboe@fb.com>
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 <axboe@fb.com>

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

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: mtip32xx: add a status field to struct mtip_cmd
  2017-04-21 14:14 ` Jens Axboe
@ 2017-04-21 14:37   ` Christoph Hellwig
  2017-04-21 14:47     ` Jens Axboe
  0 siblings, 1 reply; 4+ messages in thread
From: Christoph Hellwig @ 2017-04-21 14:37 UTC (permalink / raw)
  To: Jens Axboe
  Cc: Colin Ian King, Christoph Hellwig, Johannes Thumshirn, linux-kernel

On Fri, Apr 21, 2017 at 08:14:03AM -0600, Jens Axboe wrote:
> From: Jens Axboe <axboe@fb.com>
> 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 <axboe@fb.com>

Looks fine:

Reviewed-by: Christoph Hellwig <hch@lst.de>

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: mtip32xx: add a status field to struct mtip_cmd
  2017-04-21 14:37   ` Christoph Hellwig
@ 2017-04-21 14:47     ` Jens Axboe
  0 siblings, 0 replies; 4+ messages in thread
From: Jens Axboe @ 2017-04-21 14:47 UTC (permalink / raw)
  To: Christoph Hellwig; +Cc: Colin Ian King, Johannes Thumshirn, linux-kernel

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 <axboe@fb.com>
>> 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 <axboe@fb.com>
> 
> Looks fine:
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Pushed, thanks.

-- 
Jens Axboe

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2017-04-21 19:19 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-04-21 14:06 mtip32xx: add a status field to struct mtip_cmd Colin Ian King
2017-04-21 14:14 ` Jens Axboe
2017-04-21 14:37   ` Christoph Hellwig
2017-04-21 14:47     ` Jens Axboe

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