Re: [patch] hpsa: fix an sprintf() overflow in the reset handler

[walter harms <wharms@bfs.de>]

Am 04.06.2015 16:47, schrieb Dan Carpenter:
> The string "cmd %d RESET FAILED, new lockup detected" is not quite
> large enough so the sprintf() will overflow.  I have increased the size
> of the buffer and also changed the sprintf calls to snprintf.
> 
> Fixes: 73153fe533bc ('hpsa: use block layer tag for command allocation')
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> 
> diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
> index 1dafeb4..cab4e98 100644
> --- a/drivers/scsi/hpsa.c
> +++ b/drivers/scsi/hpsa.c
> @@ -5104,7 +5104,7 @@ static int hpsa_eh_device_reset_handler(struct scsi_cmnd *scsicmd)
>  	int rc;
>  	struct ctlr_info *h;
>  	struct hpsa_scsi_dev_t *dev;
> -	char msg[40];
> +	char msg[48];
>  
>  	/* find the controller to which the command to be aborted was sent */
>  	h = sdev_to_hba(scsicmd->device);
> @@ -5122,16 +5122,18 @@ static int hpsa_eh_device_reset_handler(struct scsi_cmnd *scsicmd)
>  
>  	/* if controller locked up, we can guarantee command won't complete */
>  	if (lockup_detected(h)) {
> -		sprintf(msg, "cmd %d RESET FAILED, lockup detected",
> -				hpsa_get_cmd_index(scsicmd));
> +		snprintf(msg, sizeof(msg),
> +			 "cmd %d RESET FAILED, lockup detected",
> +			 hpsa_get_cmd_index(scsicmd));
>  		hpsa_show_dev_msg(KERN_WARNING, h, dev, msg);
>  		return FAILED;
>  	}
>  
>  	/* this reset request might be the result of a lockup; check */
>  	if (detect_controller_lockup(h)) {
> -		sprintf(msg, "cmd %d RESET FAILED, new lockup detected",
> -				hpsa_get_cmd_index(scsicmd));
> +		snprintf(msg, sizeof(msg),
> +			 "cmd %d RESET FAILED, new lockup detected",
> +			 hpsa_get_cmd_index(scsicmd));
>  		hpsa_show_dev_msg(KERN_WARNING, h, dev, msg);
>  		return FAILED;
>  	}
> @@ -5145,7 +5147,8 @@ static int hpsa_eh_device_reset_handler(struct scsi_cmnd *scsicmd)
>  	/* send a reset to the SCSI LUN which the command was sent to */
>  	rc = hpsa_do_reset(h, dev, dev->scsi3addr, HPSA_RESET_TYPE_LUN,
>  			   DEFAULT_REPLY_QUEUE);
> -	sprintf(msg, "reset %s", rc = 0 ? "completed successfully" : "failed");
> +	snprintf(msg, sizeof(msg), "reset %s",
> +		 rc = 0 ? "completed successfully" : "failed");
>  	hpsa_show_dev_msg(KERN_WARNING, h, dev, msg);
>  	return rc = 0 ? SUCCESS : FAILED;
>  }


there is something called dev_printk_emit() what seems the varg version of dev_printk()
(what is behind psa_show_dev_msg()) maybe it would be better to redefine the interface
to use varargs ?

Its up to the maintainer to decide, i do not know how often hpsa_show_dev_msg is actualy used.

just my 2 cents,
 wh