Hi Chanwoo,

Quoting Chanwoo Choi <cw00.c...@samsung.com>:

On 2017년 12월 07일 05:20, Gustavo A. R. Silva wrote:
df->governor is being dereferenced before it is null checked,
hence there is a potential null pointer dereference.

Notice that df->governor is being null checked at line 1004:
if (df->governor) {, which implies it might be null.

Fix this by null checking df->governor before dereferencing it.

Addresses-Coverity-ID: 1401988 ("Dereference before null check")
Fixes: bcf23c79c4e4 ("PM / devfreq: Fix available_governor sysfs")
Signed-off-by: Gustavo A. R. Silva <garsi...@embeddedor.com>
---
 drivers/devfreq/devfreq.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 78fb496..14fe76b 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -996,7 +996,8 @@ static ssize_t governor_store(struct device *dev, struct device_attribute *attr,
        if (df->governor == governor) {
                ret = 0;
                goto out;
-       } else if (df->governor->immutable || governor->immutable) {
+       } else if ((df->governor && df->governor->immutable) ||
+                                       governor->immutable) {
                ret = -EINVAL;
                goto out;
        }


Actually, df->governor would be never NULL because devfreq_add_device()
initializes the ->governor always. But, governor_store() doesn't know it.


I got it.

So, looks good to me.
Reviewed-by: Chanwoo Choi <cw00.c...@samsung.com>


Thank you

--
Gustavo A. R. Silva





Reply via email to