[PATCH][next] reset: fix null pointer dereference on dev by dev_name

From: Colin King
Date: Wed Nov 14 2018 - 16:49:39 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

The call to dev_name will dereference dev, however, dev is later
being null checked, so there is a possibility of a null pointer
dereference on dev by the call to dev_name. Fix this by null
checking dev first before the call to dev_name

Detected by CoverityScan, CID#1475475 ("Dereference before null check")

Fixes: 2a6cb2b1d83b ("reset: Add reset_control_get_count()")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
drivers/reset/core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index 7f95fcb7805d..3d9a887c217e 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -799,12 +799,13 @@ EXPORT_SYMBOL_GPL(devm_reset_control_array_get);
static int reset_control_get_count_from_lookup(struct device *dev)
{
const struct reset_control_lookup *lookup;
- const char *dev_id = dev_name(dev);
+ const char *dev_id;
int count = 0;

if (!dev)
return -EINVAL;

+ dev_id = dev_name(dev);
mutex_lock(&reset_lookup_mutex);

list_for_each_entry(lookup, &reset_lookup_list, list) {
--
2.19.1