2012-08-15 20:42:30

by Alexey Khoroshilov

[permalink] [raw]
Subject: [PATCH] [media] ddbridge: fix error handling in module_init_ddbridge()

If pci_register_driver() failed, resources allocated in
ddb_class_create() are leaked. The patch fixes it.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <[email protected]>
---
drivers/media/dvb/ddbridge/ddbridge-core.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/media/dvb/ddbridge/ddbridge-core.c b/drivers/media/dvb/ddbridge/ddbridge-core.c
index ebf3f05..36aa4e4 100644
--- a/drivers/media/dvb/ddbridge/ddbridge-core.c
+++ b/drivers/media/dvb/ddbridge/ddbridge-core.c
@@ -1705,7 +1705,11 @@ static __init int module_init_ddbridge(void)
"Copyright (C) 2010-11 Digital Devices GmbH\n");
if (ddb_class_create())
return -1;
- return pci_register_driver(&ddb_pci_driver);
+ if (pci_register_driver(&ddb_pci_driver) < 0) {
+ ddb_class_destroy();
+ return -1;
+ }
+ return 0;
}

static __exit void module_exit_ddbridge(void)
--
1.7.9.5


2012-08-15 21:07:17

by Lars Hanisch

[permalink] [raw]
Subject: Re: [PATCH] [media] ddbridge: fix error handling in module_init_ddbridge()

Hi,

Am 15.08.2012 22:42, schrieb Alexey Khoroshilov:
> If pci_register_driver() failed, resources allocated in
> ddb_class_create() are leaked. The patch fixes it.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Alexey Khoroshilov <[email protected]>
> ---
> drivers/media/dvb/ddbridge/ddbridge-core.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/dvb/ddbridge/ddbridge-core.c b/drivers/media/dvb/ddbridge/ddbridge-core.c
> index ebf3f05..36aa4e4 100644
> --- a/drivers/media/dvb/ddbridge/ddbridge-core.c
> +++ b/drivers/media/dvb/ddbridge/ddbridge-core.c
> @@ -1705,7 +1705,11 @@ static __init int module_init_ddbridge(void)
> "Copyright (C) 2010-11 Digital Devices GmbH\n");
> if (ddb_class_create())
> return -1;
> - return pci_register_driver(&ddb_pci_driver);
> + if (pci_register_driver(&ddb_pci_driver) < 0) {
> + ddb_class_destroy();
> + return -1;

Difference to before: the return value of pci_register_driver is not passed through.
Is this a problem? I'm just an interested application developer, not a driver developer.

Regards,
Lars.

> + }
> + return 0;
> }
>
> static __exit void module_exit_ddbridge(void)
>

2012-08-15 23:14:12

by Mauro Carvalho Chehab

[permalink] [raw]
Subject: Re: [PATCH] [media] ddbridge: fix error handling in module_init_ddbridge()

Em 15-08-2012 18:00, Lars Hanisch escreveu:
> Hi,
>
> Am 15.08.2012 22:42, schrieb Alexey Khoroshilov:
>> If pci_register_driver() failed, resources allocated in
>> ddb_class_create() are leaked. The patch fixes it.
>>
>> Found by Linux Driver Verification project (linuxtesting.org).
>>
>> Signed-off-by: Alexey Khoroshilov <[email protected]>
>> ---
>> drivers/media/dvb/ddbridge/ddbridge-core.c | 6 +++++-
>> 1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/media/dvb/ddbridge/ddbridge-core.c b/drivers/media/dvb/ddbridge/ddbridge-core.c
>> index ebf3f05..36aa4e4 100644
>> --- a/drivers/media/dvb/ddbridge/ddbridge-core.c
>> +++ b/drivers/media/dvb/ddbridge/ddbridge-core.c
>> @@ -1705,7 +1705,11 @@ static __init int module_init_ddbridge(void)
>> "Copyright (C) 2010-11 Digital Devices GmbH\n");
>> if (ddb_class_create())
>> return -1;

This is not right. It should be returning a proper error code.

Could you please patch ddb_class_create() in order to make it to
return the retuned value from IS_ERR() as the error code, and return
it back to the init code?

Ok, I noticed that other parts of the driver are also returning wrong
error codes, but let's fix at least module_init_ddbridge() while you're
looking into this.

>> - return pci_register_driver(&ddb_pci_driver);
>> + if (pci_register_driver(&ddb_pci_driver) < 0) {
>> + ddb_class_destroy();
>> + return -1;

Again, the correct here would be to store the error on a temp register
and return it, instead of returning -1.
>
> Difference to before: the return value of pci_register_driver is not passed through.
> Is this a problem? I'm just an interested application developer, not a driver developer.

On userspace, ioctl() always return -1 on errors. The error code at "errno"
is wrong, though. Instead of "1", it should be the ones described at the
API spec[1].

[1] http://linuxtv.org/downloads/v4l-dvb-apis/gen_errors.html

>
> Regards,
> Lars.
>
>> + }
>> + return 0;
>> }
>>
>> static __exit void module_exit_ddbridge(void)
>>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>

2012-08-16 09:26:41

by Mauro Carvalho Chehab

[permalink] [raw]
Subject: Re: [PATCH] [media] ddbridge: fix error handling in module_init_ddbridge()

Em 15-08-2012 17:42, Alexey Khoroshilov escreveu:
> If pci_register_driver() failed, resources allocated in
> ddb_class_create() are leaked. The patch fixes it.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Alexey Khoroshilov <[email protected]>
> ---
> drivers/media/dvb/ddbridge/ddbridge-core.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/dvb/ddbridge/ddbridge-core.c b/drivers/media/dvb/ddbridge/ddbridge-core.c
> index ebf3f05..36aa4e4 100644
> --- a/drivers/media/dvb/ddbridge/ddbridge-core.c
> +++ b/drivers/media/dvb/ddbridge/ddbridge-core.c
> @@ -1705,7 +1705,11 @@ static __init int module_init_ddbridge(void)
> "Copyright (C) 2010-11 Digital Devices GmbH\n");
> if (ddb_class_create())
> return -1;

This is not right. It should be returning a proper error code.

Could you please patch ddb_class_create() in order to make it to
return the retuned value from IS_ERR() as the error code, and return
it back to the init code?

Ok, I noticed that other parts of the driver are also returning wrong
error codes, but let's fix at least module_init_ddbridge() while you're
looking into this.

> - return pci_register_driver(&ddb_pci_driver);
> + if (pci_register_driver(&ddb_pci_driver) < 0) {
> + ddb_class_destroy();
> + return -1;

The correct here would be to store the error on a temp register
and return it, instead of returning -1.

> + }
> + return 0;
> }
>
> static __exit void module_exit_ddbridge(void)
>

Thank you!
Mauro

2012-08-16 09:36:53

by Mauro Carvalho Chehab

[permalink] [raw]
Subject: Re: [PATCH] [media] ddbridge: fix error handling in module_init_ddbridge()

Em 16-08-2012 06:26, Mauro Carvalho Chehab escreveu:
> Em 15-08-2012 17:42, Alexey Khoroshilov escreveu:
>> If pci_register_driver() failed, resources allocated in
>> ddb_class_create() are leaked. The patch fixes it.
>>
>> Found by Linux Driver Verification project (linuxtesting.org).
>>
>> Signed-off-by: Alexey Khoroshilov <[email protected]>
>> ---
>> drivers/media/dvb/ddbridge/ddbridge-core.c | 6 +++++-
>> 1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/media/dvb/ddbridge/ddbridge-core.c b/drivers/media/dvb/ddbridge/ddbridge-core.c
>> index ebf3f05..36aa4e4 100644
>> --- a/drivers/media/dvb/ddbridge/ddbridge-core.c
>> +++ b/drivers/media/dvb/ddbridge/ddbridge-core.c
>> @@ -1705,7 +1705,11 @@ static __init int module_init_ddbridge(void)
>> "Copyright (C) 2010-11 Digital Devices GmbH\n");
>> if (ddb_class_create())
>> return -1;
>
> This is not right. It should be returning a proper error code.

Please discard this email. I already commented this on a previous email.
This one was a previous draft.

Thanks,
Mauro

>
> Could you please patch ddb_class_create() in order to make it to
> return the retuned value from IS_ERR() as the error code, and return
> it back to the init code?
>
> Ok, I noticed that other parts of the driver are also returning wrong
> error codes, but let's fix at least module_init_ddbridge() while you're
> looking into this.
>
>> - return pci_register_driver(&ddb_pci_driver);
>> + if (pci_register_driver(&ddb_pci_driver) < 0) {
>> + ddb_class_destroy();
>> + return -1;
>
> The correct here would be to store the error on a temp register
> and return it, instead of returning -1.
>
>> + }
>> + return 0;
>> }
>>
>> static __exit void module_exit_ddbridge(void)
>>
>
> Thank you!
> Mauro
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>