2016-12-22 09:52:30

by Jaehoon Chung

Subject: [PATCH] phy: core: check whether ops callback function is assigned

If some ops-> callback function are not assigend, then it should do the
unexpect behavior.
To prevent the potential NULL pointer dereference, check the each
callback functions before doing operation.

Signed-off-by: Jaehoon Chung <[email protected]>
---
drivers/phy/phy-core.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
index a268f4d6f3e9..e4eb4431c8a4 100644
--- a/drivers/phy/phy-core.c
+++ b/drivers/phy/phy-core.c
@@ -219,7 +219,7 @@ int phy_init(struct phy *phy)
{
int ret;

- if (!phy)
+ if (!phy || !phy->ops->init)
return 0;

ret = phy_pm_runtime_get_sync(phy);
@@ -248,7 +248,7 @@ int phy_exit(struct phy *phy)
{
int ret;

- if (!phy)
+ if (!phy || !phy->ops->exit)
return 0;

ret = phy_pm_runtime_get_sync(phy);
@@ -277,7 +277,7 @@ int phy_power_on(struct phy *phy)
{
int ret = 0;

- if (!phy)
+ if (!phy || !phy->ops->power_on)
goto out;

if (phy->pwr) {
@@ -319,7 +319,7 @@ int phy_power_off(struct phy *phy)
{
int ret;

- if (!phy)
+ if (!phy || !phy->ops->power_off)
return 0;

mutex_lock(&phy->mutex);
--
2.11.0

2016-12-27 08:32:25

by Kishon Vijay Abraham I

Subject: Re: [PATCH] phy: core: check whether ops callback function is assigned

Hi,

On Thursday 22 December 2016 03:12 PM, Jaehoon Chung wrote:
> If some ops-> callback function are not assigend, then it should do the
> unexpect behavior.
> To prevent the potential NULL pointer dereference, check the each
> callback functions before doing operation.

The call backs checks are done after the mutex. Moreover even if the call backs
are not assigned, the user can call the phy ops for doing pm_runtime.

Thanks
Kishon

>
> Signed-off-by: Jaehoon Chung <[email protected]>
> ---
> drivers/phy/phy-core.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
> index a268f4d6f3e9..e4eb4431c8a4 100644
> --- a/drivers/phy/phy-core.c
> +++ b/drivers/phy/phy-core.c
> @@ -219,7 +219,7 @@ int phy_init(struct phy *phy)
> {
> int ret;
>
> - if (!phy)
> + if (!phy || !phy->ops->init)
> return 0;
>
> ret = phy_pm_runtime_get_sync(phy);
> @@ -248,7 +248,7 @@ int phy_exit(struct phy *phy)
> {
> int ret;
>
> - if (!phy)
> + if (!phy || !phy->ops->exit)
> return 0;
>
> ret = phy_pm_runtime_get_sync(phy);
> @@ -277,7 +277,7 @@ int phy_power_on(struct phy *phy)
> {
> int ret = 0;
>
> - if (!phy)
> + if (!phy || !phy->ops->power_on)
> goto out;
>
> if (phy->pwr) {
> @@ -319,7 +319,7 @@ int phy_power_off(struct phy *phy)
> {
> int ret;
>
> - if (!phy)
> + if (!phy || !phy->ops->power_off)
> return 0;
>
> mutex_lock(&phy->mutex);
>

2016-12-27 08:37:44

by Jaehoon Chung

Subject: Re: [PATCH] phy: core: check whether ops callback function is assigned

On 12/27/2016 05:31 PM, Kishon Vijay Abraham I wrote:
> Hi,
>
> On Thursday 22 December 2016 03:12 PM, Jaehoon Chung wrote:
>> If some ops-> callback function are not assigend, then it should do the
>> unexpect behavior.
>> To prevent the potential NULL pointer dereference, check the each
>> callback functions before doing operation.
>
> The call backs checks are done after the mutex. Moreover even if the call backs
> are not assigned, the user can call the phy ops for doing pm_runtime.

Yes. I found this patch also is wrong. Thanks for pointing out.

Best Regards,
Jaehoon Chung

>
> Thanks
> Kishon
>
>>
>> Signed-off-by: Jaehoon Chung <[email protected]>
>> ---
>> drivers/phy/phy-core.c | 8 ++++----
>> 1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
>> index a268f4d6f3e9..e4eb4431c8a4 100644
>> --- a/drivers/phy/phy-core.c
>> +++ b/drivers/phy/phy-core.c
>> @@ -219,7 +219,7 @@ int phy_init(struct phy *phy)
>> {
>> int ret;
>>
>> - if (!phy)
>> + if (!phy || !phy->ops->init)
>> return 0;
>>
>> ret = phy_pm_runtime_get_sync(phy);
>> @@ -248,7 +248,7 @@ int phy_exit(struct phy *phy)
>> {
>> int ret;
>>
>> - if (!phy)
>> + if (!phy || !phy->ops->exit)
>> return 0;
>>
>> ret = phy_pm_runtime_get_sync(phy);
>> @@ -277,7 +277,7 @@ int phy_power_on(struct phy *phy)
>> {
>> int ret = 0;
>>
>> - if (!phy)
>> + if (!phy || !phy->ops->power_on)
>> goto out;
>>
>> if (phy->pwr) {
>> @@ -319,7 +319,7 @@ int phy_power_off(struct phy *phy)
>> {
>> int ret;
>>
>> - if (!phy)
>> + if (!phy || !phy->ops->power_off)
>> return 0;
>>
>> mutex_lock(&phy->mutex);
>>
>
>
>