scsi: aic79xx: add scb NULL check in ahd_handle_msg_reject()

[PATCH] scsi: aic79xx: add scb NULL check in ahd_handle_msg_reject()

Posted by Aleksandr Aprelkov 1 year, 10 months ago

If ahd_lookup_scb() returns NULL and ahd_sent_msg() checks are false,
then NULL pointer dereference happens

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Aleksandr Aprelkov <aaprelkov@usergate.com>
---
 drivers/scsi/aic7xxx/aic79xx_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/aic7xxx/aic79xx_core.c b/drivers/scsi/aic7xxx/aic79xx_core.c
index 3e3100dbfda3..9e0fafa12e87 100644
--- a/drivers/scsi/aic7xxx/aic79xx_core.c
+++ b/drivers/scsi/aic7xxx/aic79xx_core.c
@@ -5577,7 +5577,7 @@ ahd_handle_msg_reject(struct ahd_softc *ahd, struct ahd_devinfo *devinfo)
 		       "Using asynchronous transfers\n",
 		       ahd_name(ahd), devinfo->channel,
 		       devinfo->target, devinfo->lun);
-	} else if ((scb->hscb->control & SIMPLE_QUEUE_TAG) != 0) {
+	} else if (scb && (scb->hscb->control & SIMPLE_QUEUE_TAG) != 0) {
 		int tag_type;
 		int mask;
 
-- 
2.34.1

Re: [PATCH] scsi: aic79xx: add scb NULL check in ahd_handle_msg_reject()

Posted by Damien Le Moal 1 year, 10 months ago

On 4/1/24 15:10, Aleksandr Aprelkov wrote:
> If ahd_lookup_scb() returns NULL and ahd_sent_msg() checks are false,
> then NULL pointer dereference happens
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Aleksandr Aprelkov <aaprelkov@usergate.com>
> ---
>  drivers/scsi/aic7xxx/aic79xx_core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/scsi/aic7xxx/aic79xx_core.c b/drivers/scsi/aic7xxx/aic79xx_core.c
> index 3e3100dbfda3..9e0fafa12e87 100644
> --- a/drivers/scsi/aic7xxx/aic79xx_core.c
> +++ b/drivers/scsi/aic7xxx/aic79xx_core.c
> @@ -5577,7 +5577,7 @@ ahd_handle_msg_reject(struct ahd_softc *ahd, struct ahd_devinfo *devinfo)
>  		       "Using asynchronous transfers\n",
>  		       ahd_name(ahd), devinfo->channel,
>  		       devinfo->target, devinfo->lun);
> -	} else if ((scb->hscb->control & SIMPLE_QUEUE_TAG) != 0) {
> +	} else if (scb && (scb->hscb->control & SIMPLE_QUEUE_TAG) != 0) {

"!= 0" is not needed.

>  		int tag_type;
>  		int mask;
>  

-- 
Damien Le Moal
Western Digital Research