if device_register() returned an error! Always use put_device()
to give up the reference initialized.
Signed-off-by: Arvind Yadav <[email protected]>
---
change in v2:
Fix use-after-free bug. move put_device() after cdev_del().
drivers/mtd/ubi/vmt.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
index 3fd8d7f..93c6163 100644
--- a/drivers/mtd/ubi/vmt.c
+++ b/drivers/mtd/ubi/vmt.c
@@ -610,6 +610,7 @@ int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol)
out_cdev:
cdev_del(&vol->cdev);
+ put_device(&vol->dev);
return err;
}
--
1.9.1
Am Donnerstag, 15. M?rz 2018, 08:20:31 CET schrieb Arvind Yadav:
> if device_register() returned an error! Always use put_device()
> to give up the reference initialized.
Like DaveM said, there is no need to shout and use "!".
> Signed-off-by: Arvind Yadav <[email protected]>
> ---
> change in v2:
> Fix use-after-free bug. move put_device() after cdev_del().
>
> drivers/mtd/ubi/vmt.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
> index 3fd8d7f..93c6163 100644
> --- a/drivers/mtd/ubi/vmt.c
> +++ b/drivers/mtd/ubi/vmt.c
> @@ -610,6 +610,7 @@ int ubi_add_volume(struct ubi_device *ubi, struct
> ubi_volume *vol)
>
> out_cdev:
> cdev_del(&vol->cdev);
> + put_device(&vol->dev);
> return err;
The more I dig into device code, the more questions I have.
Why is cdev_del() not part of the release function?
Thanks,
//richard
On Thursday 15 March 2018 01:25 PM, Richard Weinberger wrote:
> Am Donnerstag, 15. M?rz 2018, 08:20:31 CET schrieb Arvind Yadav:
>> if device_register() returned an error! Always use put_device()
>> to give up the reference initialized.
> Like DaveM said, there is no need to shout and use "!".
I will fix this and send you update patch.
>
>> Signed-off-by: Arvind Yadav <[email protected]>
>> ---
>> change in v2:
>> Fix use-after-free bug. move put_device() after cdev_del().
>>
>> drivers/mtd/ubi/vmt.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
>> index 3fd8d7f..93c6163 100644
>> --- a/drivers/mtd/ubi/vmt.c
>> +++ b/drivers/mtd/ubi/vmt.c
>> @@ -610,6 +610,7 @@ int ubi_add_volume(struct ubi_device *ubi, struct
>> ubi_volume *vol)
>>
>> out_cdev:
>> cdev_del(&vol->cdev);
>> + put_device(&vol->dev);
>> return err;
> The more I dig into device code, the more questions I have.
> Why is cdev_del() not part of the release function?
>
> Thanks,
> //richard
Yes, It's should be a part release function.
~arvind
On Thursday 15 March 2018 02:17 PM, Arvind Yadav wrote:
>
>
> On Thursday 15 March 2018 01:25 PM, Richard Weinberger wrote:
>> Am Donnerstag, 15. M?rz 2018, 08:20:31 CET schrieb Arvind Yadav:
>>> if device_register() returned an error! Always use put_device()
>>> to give up the reference initialized.
>> Like DaveM said, there is no need to shout and use "!".
>
> I will fix this and send you update patch.
>>> Signed-off-by: Arvind Yadav <[email protected]>
>>> ---
>>> change in v2:
>>> Fix use-after-free bug. move put_device() after cdev_del().
>>>
>>> drivers/mtd/ubi/vmt.c | 1 +
>>> 1 file changed, 1 insertion(+)
>>>
>>> diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
>>> index 3fd8d7f..93c6163 100644
>>> --- a/drivers/mtd/ubi/vmt.c
>>> +++ b/drivers/mtd/ubi/vmt.c
>>> @@ -610,6 +610,7 @@ int ubi_add_volume(struct ubi_device *ubi, struct
>>> ubi_volume *vol)
>>>
>>> out_cdev:
>>> cdev_del(&vol->cdev);
>>> + put_device(&vol->dev);
>>> return err;
>> The more I dig into device code, the more questions I have.
>> Why is cdev_del() not part of the release function?
>>
>> Thanks,
>> //richard
>
> Yes, It's should be a part release function.
>
> ~arvind
I was wrong, We can not add cdev_del() in release(vol_release)
function.
Function's ubi_create_volume and ubi_add_volume both are using
same release function to release a volume devices.
ubi_add_volume is registering character device for the volume.
So we will have to release character device here.
~arvind
Arvind,
Am Donnerstag, 15. M?rz 2018, 18:41:58 CET schrieb arvindY:
> On Thursday 15 March 2018 02:17 PM, Arvind Yadav wrote:
> > On Thursday 15 March 2018 01:25 PM, Richard Weinberger wrote:
> >> Am Donnerstag, 15. M?rz 2018, 08:20:31 CET schrieb Arvind Yadav:
> >>> if device_register() returned an error! Always use put_device()
> >>> to give up the reference initialized.
> >>
> >> Like DaveM said, there is no need to shout and use "!".
> >
> > I will fix this and send you update patch.
> >
> >>> Signed-off-by: Arvind Yadav <[email protected]>
> >>> ---
> >>>
> >>> change in v2:
> >>> Fix use-after-free bug. move put_device() after cdev_del().
> >>>
> >>> drivers/mtd/ubi/vmt.c | 1 +
> >>> 1 file changed, 1 insertion(+)
> >>>
> >>> diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
> >>> index 3fd8d7f..93c6163 100644
> >>> --- a/drivers/mtd/ubi/vmt.c
> >>> +++ b/drivers/mtd/ubi/vmt.c
> >>> @@ -610,6 +610,7 @@ int ubi_add_volume(struct ubi_device *ubi, struct
> >>> ubi_volume *vol)
> >>>
> >>> out_cdev:
> >>> cdev_del(&vol->cdev);
> >>>
> >>> + put_device(&vol->dev);
> >>>
> >>> return err;
> >>
> >> The more I dig into device code, the more questions I have.
> >> Why is cdev_del() not part of the release function?
> >>
> >> Thanks,
> >> //richard
> >
> > Yes, It's should be a part release function.
> >
> > ~arvind
>
> I was wrong, We can not add cdev_del() in release(vol_release)
> function.
> Function's ubi_create_volume and ubi_add_volume both are using
> same release function to release a volume devices.
> ubi_add_volume is registering character device for the volume.
> So we will have to release character device here.
This is not what I meant.
The question was whether we should free all this data structures from the
device model's point of view.
That we have to massage UBI code for that is clear.
Thanks,
//richard