[PATCH] reset: fix potential null pointer dereference on pointer dev

From: Colin King
Date: Thu May 09 2019 - 12:01:51 EST

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

Pointer dev is being dereferenced when passed to the inlined
functon dev_name, however, dev is later being null checked.
Thus there is a potential null pointer dereference on a null
dev. Fix this by performing the null check on dev before
dereferencing it.

Addresses-Coverity: ("Dereference before null check")
Fixes: 6691dffab0ab ("reset: add support for non-DT systems")
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 81ea77cba123..83f1a1d5ee67 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -691,12 +691,13 @@ __reset_control_get_from_lookup(struct device *dev, const char *con_id,
const struct reset_control_lookup *lookup;
struct reset_controller_dev *rcdev;
- const char *dev_id = dev_name(dev);
+ const char *dev_id;
struct reset_control *rstc = NULL;

if (!dev)
return ERR_PTR(-EINVAL);

+ dev_id = dev_name(dev);

list_for_each_entry(lookup, &reset_lookup_list, list) {