Messages in this thread Patch in this message | | | From | Cristian Marussi <> | Subject | [PATCH] firmware: arm_scmi: Fix late checks on pointer dereference | Date | Tue, 3 May 2022 13:10:47 +0100 |
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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.
Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> --- drivers/firmware/arm_scmi/driver.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-)
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index c4960fd3df75..c1922bd650ae 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -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; -- 2.32.0
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