Hi Chanwoo, Quoting Chanwoo Choi <[email protected]>:
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 <[email protected]> --- 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 <[email protected]>
Thank you -- Gustavo A. R. Silva
