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

walter harms
2015-06-04T15:22:41Z

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