2019-03-20 16:27:33

by Aditya Pakki

Subject: [PATCH v2] thunderbolt: Fix to check return value of ida_simple_get

In enumerate_services, ida_simple_get on failure can return an error and
leaks memory during device_register failure. The patch ensures that
the dev_set_name is set on non failure cases, and releases memory in
case of failure.

Signed-off-by: Aditya Pakki <[email protected]>

---
v1: Missed cleanup of svc in case of allocation failure and
device_register failure.
---
drivers/thunderbolt/xdomain.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/thunderbolt/xdomain.c b/drivers/thunderbolt/xdomain.c
index e27dd8beb94b..eb08275185bf 100644
--- a/drivers/thunderbolt/xdomain.c
+++ b/drivers/thunderbolt/xdomain.c
@@ -740,6 +740,7 @@ static void enumerate_services(struct tb_xdomain *xd)
struct tb_service *svc;
struct tb_property *p;
struct device *dev;
+ int id;

/*
* First remove all services that are not available anymore in
@@ -768,7 +769,12 @@ static void enumerate_services(struct tb_xdomain *xd)
break;
}

- svc->id = ida_simple_get(&xd->service_ids, 0, 0, GFP_KERNEL);
+ id = ida_simple_get(&xd->service_ids, 0, 0, GFP_KERNEL);
+ if (id < 0) {
+ kfree(svc);
+ break;
+ }
+ svc->id = id;
svc->dev.bus = &tb_bus_type;
svc->dev.type = &tb_service_type;
svc->dev.parent = &xd->dev;
@@ -776,6 +782,7 @@ static void enumerate_services(struct tb_xdomain *xd)

if (device_register(&svc->dev)) {
put_device(&svc->dev);
+ kfree(svc);
break;
}
}
--
2.17.1

2019-03-20 16:30:26

by Mika Westerberg

Subject: Re: [PATCH v2] thunderbolt: Fix to check return value of ida_simple_get

On Wed, Mar 20, 2019 at 11:24:45AM -0500, Aditya Pakki wrote:
> In enumerate_services, ida_simple_get on failure can return an error and
> leaks memory during device_register failure. The patch ensures that
> the dev_set_name is set on non failure cases, and releases memory in
> case of failure.
>
> Signed-off-by: Aditya Pakki <[email protected]>
>
> ---
> v1: Missed cleanup of svc in case of allocation failure and
> device_register failure.
> ---
> drivers/thunderbolt/xdomain.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/thunderbolt/xdomain.c b/drivers/thunderbolt/xdomain.c
> index e27dd8beb94b..eb08275185bf 100644
> --- a/drivers/thunderbolt/xdomain.c
> +++ b/drivers/thunderbolt/xdomain.c
> @@ -740,6 +740,7 @@ static void enumerate_services(struct tb_xdomain *xd)
> struct tb_service *svc;
> struct tb_property *p;
> struct device *dev;
> + int id;
>
> /*
> * First remove all services that are not available anymore in
> @@ -768,7 +769,12 @@ static void enumerate_services(struct tb_xdomain *xd)
> break;
> }
>
> - svc->id = ida_simple_get(&xd->service_ids, 0, 0, GFP_KERNEL);
> + id = ida_simple_get(&xd->service_ids, 0, 0, GFP_KERNEL);
> + if (id < 0) {
> + kfree(svc);
> + break;
> + }
> + svc->id = id;
> svc->dev.bus = &tb_bus_type;
> svc->dev.type = &tb_service_type;
> svc->dev.parent = &xd->dev;
> @@ -776,6 +782,7 @@ static void enumerate_services(struct tb_xdomain *xd)
>
> if (device_register(&svc->dev)) {
> put_device(&svc->dev);
> + kfree(svc);

You can't do this after device_register() is called. The put_device()
above is sufficient.

2019-03-20 20:41:26

by Mukesh Ojha

Subject: Re: [PATCH v2] thunderbolt: Fix to check return value of ida_simple_get

On 3/20/2019 9:59 PM, Mika Westerberg wrote:
> On Wed, Mar 20, 2019 at 11:24:45AM -0500, Aditya Pakki wrote:
>> In enumerate_services, ida_simple_get on failure can return an error and
>> leaks memory during device_register failure. The patch ensures that
>> the dev_set_name is set on non failure cases, and releases memory in
>> case of failure.
>>
>> Signed-off-by: Aditya Pakki <[email protected]>
>>
>> ---
>> v1: Missed cleanup of svc in case of allocation failure and
>> device_register failure.
>> ---
>> drivers/thunderbolt/xdomain.c | 9 ++++++++-
>> 1 file changed, 8 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/thunderbolt/xdomain.c b/drivers/thunderbolt/xdomain.c
>> index e27dd8beb94b..eb08275185bf 100644
>> --- a/drivers/thunderbolt/xdomain.c
>> +++ b/drivers/thunderbolt/xdomain.c
>> @@ -740,6 +740,7 @@ static void enumerate_services(struct tb_xdomain *xd)
>> struct tb_service *svc;
>> struct tb_property *p;
>> struct device *dev;
>> + int id;
>>
>> /*
>> * First remove all services that are not available anymore in
>> @@ -768,7 +769,12 @@ static void enumerate_services(struct tb_xdomain *xd)
>> break;
>> }
>>
>> - svc->id = ida_simple_get(&xd->service_ids, 0, 0, GFP_KERNEL);
>> + id = ida_simple_get(&xd->service_ids, 0, 0, GFP_KERNEL);
>> + if (id < 0) {
>> + kfree(svc);
>> + break;
>> + }
>> + svc->id = id;
>> svc->dev.bus = &tb_bus_type;
>> svc->dev.type = &tb_service_type;
>> svc->dev.parent = &xd->dev;
>> @@ -776,6 +782,7 @@ static void enumerate_services(struct tb_xdomain *xd)
>>
>> if (device_register(&svc->dev)) {
>> put_device(&svc->dev);
>> + kfree(svc);
> You can't do this after device_register() is called. The put_device()
> above is sufficient.


If  device_register fails, how would svc gets freed? we need  to kfree
svc here as well.

Thanks,
Mukesh

2019-03-21 05:51:02

by Mika Westerberg

Subject: Re: [PATCH v2] thunderbolt: Fix to check return value of ida_simple_get

On Thu, Mar 21, 2019 at 02:09:41AM +0530, Mukesh Ojha wrote:
>
> On 3/20/2019 9:59 PM, Mika Westerberg wrote:
> > On Wed, Mar 20, 2019 at 11:24:45AM -0500, Aditya Pakki wrote:
> > > In enumerate_services, ida_simple_get on failure can return an error and
> > > leaks memory during device_register failure. The patch ensures that
> > > the dev_set_name is set on non failure cases, and releases memory in
> > > case of failure.
> > >
> > > Signed-off-by: Aditya Pakki <[email protected]>
> > >
> > > ---
> > > v1: Missed cleanup of svc in case of allocation failure and
> > > device_register failure.
> > > ---
> > > drivers/thunderbolt/xdomain.c | 9 ++++++++-
> > > 1 file changed, 8 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/thunderbolt/xdomain.c b/drivers/thunderbolt/xdomain.c
> > > index e27dd8beb94b..eb08275185bf 100644
> > > --- a/drivers/thunderbolt/xdomain.c
> > > +++ b/drivers/thunderbolt/xdomain.c
> > > @@ -740,6 +740,7 @@ static void enumerate_services(struct tb_xdomain *xd)
> > > struct tb_service *svc;
> > > struct tb_property *p;
> > > struct device *dev;
> > > + int id;
> > > /*
> > > * First remove all services that are not available anymore in
> > > @@ -768,7 +769,12 @@ static void enumerate_services(struct tb_xdomain *xd)
> > > break;
> > > }
> > > - svc->id = ida_simple_get(&xd->service_ids, 0, 0, GFP_KERNEL);
> > > + id = ida_simple_get(&xd->service_ids, 0, 0, GFP_KERNEL);
> > > + if (id < 0) {
> > > + kfree(svc);
> > > + break;
> > > + }
> > > + svc->id = id;
> > > svc->dev.bus = &tb_bus_type;
> > > svc->dev.type = &tb_service_type;
> > > svc->dev.parent = &xd->dev;
> > > @@ -776,6 +782,7 @@ static void enumerate_services(struct tb_xdomain *xd)
> > > if (device_register(&svc->dev)) {
> > > put_device(&svc->dev);
> > > + kfree(svc);
> > You can't do this after device_register() is called. The put_device()
> > above is sufficient.
>
>
> If? device_register fails, how would svc gets freed? we need? to kfree svc
> here as well.

Please read the comment on top of device_register(). It should explain.

So no kfree here.

2019-03-22 07:34:15

by Mukesh Ojha

Subject: Re: [PATCH v2] thunderbolt: Fix to check return value of ida_simple_get

On 3/21/2019 11:19 AM, Mika Westerberg wrote:
> On Thu, Mar 21, 2019 at 02:09:41AM +0530, Mukesh Ojha wrote:
>> On 3/20/2019 9:59 PM, Mika Westerberg wrote:
>>> On Wed, Mar 20, 2019 at 11:24:45AM -0500, Aditya Pakki wrote:
>>>> In enumerate_services, ida_simple_get on failure can return an error and
>>>> leaks memory during device_register failure. The patch ensures that
>>>> the dev_set_name is set on non failure cases, and releases memory in
>>>> case of failure.
>>>>
>>>> Signed-off-by: Aditya Pakki <[email protected]>
>>>>
>>>> ---
>>>> v1: Missed cleanup of svc in case of allocation failure and
>>>> device_register failure.
>>>> ---
>>>> drivers/thunderbolt/xdomain.c | 9 ++++++++-
>>>> 1 file changed, 8 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/thunderbolt/xdomain.c b/drivers/thunderbolt/xdomain.c
>>>> index e27dd8beb94b..eb08275185bf 100644
>>>> --- a/drivers/thunderbolt/xdomain.c
>>>> +++ b/drivers/thunderbolt/xdomain.c
>>>> @@ -740,6 +740,7 @@ static void enumerate_services(struct tb_xdomain *xd)
>>>> struct tb_service *svc;
>>>> struct tb_property *p;
>>>> struct device *dev;
>>>> + int id;
>>>> /*
>>>> * First remove all services that are not available anymore in
>>>> @@ -768,7 +769,12 @@ static void enumerate_services(struct tb_xdomain *xd)
>>>> break;
>>>> }
>>>> - svc->id = ida_simple_get(&xd->service_ids, 0, 0, GFP_KERNEL);
>>>> + id = ida_simple_get(&xd->service_ids, 0, 0, GFP_KERNEL);
>>>> + if (id < 0) {
>>>> + kfree(svc);
>>>> + break;
>>>> + }
>>>> + svc->id = id;
>>>> svc->dev.bus = &tb_bus_type;
>>>> svc->dev.type = &tb_service_type;
>>>> svc->dev.parent = &xd->dev;
>>>> @@ -776,6 +782,7 @@ static void enumerate_services(struct tb_xdomain *xd)
>>>> if (device_register(&svc->dev)) {
>>>> put_device(&svc->dev);
>>>> + kfree(svc);
>>> You can't do this after device_register() is called. The put_device()
>>> above is sufficient.
>>
>> If  device_register fails, how would svc gets freed? we need  to kfree svc
>> here as well.
> Please read the comment on top of device_register(). It should explain.
>
> So no kfree here.

Thanks for pointer Mika.

Overlooked the fact that dev is a data member of svc not a pointer, also
noticed there are many places in tree where , it is not
followed.

Thanks,
Mukesh