Commit c7f8852d authored by Cristian Marussi's avatar Cristian Marussi Committed by Sudeep Holla
Browse files

firmware: arm_scmi: Fix late checks on pointer dereference 

A few dereferences could happen before the iterator pointer argument was
checked for NULL, causing the following smatch warnings:

drivers/firmware/arm_scmi/driver.c:1214 scmi_iterator_run() warn: variable
dereferenced before check 'i' (see line 1210)

Fix by moving the checks early and dropping some unneeded local references.

No functional change.

Link: https://lore.kernel.org/r/20220503121047.3590340-1-cristian.marussi@arm.com


Reported-by: default avatarkernel test robot <lkp@intel.com>
Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarCristian Marussi <cristian.marussi@arm.com>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
parent 5e114ad9

drivers/firmware/arm_scmi/driver.c

+11 −8
Original line number Diff line number Diff line
@@ -1205,18 +1205,21 @@ static void *scmi_iterator_init(const struct scmi_protocol_handle *ph, 
static int scmi_iterator_run(void *iter)

{

	int ret = -EINVAL;

	struct scmi_iterator_ops *iops;

	const struct scmi_protocol_handle *ph;

	struct scmi_iterator_state *st;

	struct scmi_iterator *i = iter;

	struct scmi_iterator_state *st = &i->state;

	struct scmi_iterator_ops *iops = i->ops;

	const struct scmi_protocol_handle *ph = i->ph;

	const struct scmi_xfer_ops *xops = ph->xops;



	if (!i)

	if (!i || !i->ops || !i->ph)

		return ret;



	iops = i->ops;

	ph = i->ph;

	st = &i->state;



	do {

		iops->prepare_message(i->msg, st->desc_index, i->priv);

		ret = xops->do_xfer(ph, i->t);

		ret = ph->xops->do_xfer(ph, i->t);

		if (ret)

			break;
@@ -1240,7 +1243,7 @@ static int scmi_iterator_run(void *iter) 
		}



		st->desc_index += st->num_returned;

		xops->reset_rx_to_maxsz(ph, i->t);

		ph->xops->reset_rx_to_maxsz(ph, i->t);

		/*

		 * check for both returned and remaining to avoid infinite

		 * loop due to buggy firmware
@@ -1249,7 +1252,7 @@ static int scmi_iterator_run(void *iter) 


out:

	/* Finalize and destroy iterator */

	xops->xfer_put(ph, i->t);

	ph->xops->xfer_put(ph, i->t);

	devm_kfree(ph->dev, i);



	return ret;