2017-06-12 22:02:35

by Gustavo A. R. Silva

Subject: [PATCH] nfc: nci: fix potential NULL pointer dereference

NULL check at line 76: if (conn_info) {, implies that pointer conn_info
might be NULL, but this pointer is being previously dereferenced,
which might cause a NULL pointer dereference.

Add NULL check before dereferencing pointer conn_info in order to
avoid a potential NULL pointer dereference.

Addresses-Coverity-ID: 1362349
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
net/nfc/nci/core.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 61fff42..d2198ce 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -70,14 +70,13 @@ int nci_get_conn_info_by_dest_type_params(struct nci_dev *ndev, u8 dest_type,
struct nci_conn_info *conn_info;

list_for_each_entry(conn_info, &ndev->conn_info_list, list) {
- if (conn_info->dest_type == dest_type) {
+ if (conn_info && conn_info->dest_type == dest_type) {
if (!params)
return conn_info->conn_id;
- if (conn_info) {
- if (params->id == conn_info->dest_params->id &&
- params->protocol == conn_info->dest_params->protocol)
- return conn_info->conn_id;
- }
+
+ if (params->id == conn_info->dest_params->id &&
+ params->protocol == conn_info->dest_params->protocol)
+ return conn_info->conn_id;
}
}

--
2.5.0

2017-06-12 22:22:00

by Guenter Roeck

Subject: Re: nfc: nci: fix potential NULL pointer dereference

On Mon, Jun 12, 2017 at 05:02:23PM -0500, Gustavo A. R. Silva wrote:
> NULL check at line 76: if (conn_info) {, implies that pointer conn_info
> might be NULL, but this pointer is being previously dereferenced,
> which might cause a NULL pointer dereference.
>
> Add NULL check before dereferencing pointer conn_info in order to
> avoid a potential NULL pointer dereference.
>
> Addresses-Coverity-ID: 1362349
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
> net/nfc/nci/core.c | 11 +++++------
> 1 file changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
> index 61fff42..d2198ce 100644
> --- a/net/nfc/nci/core.c
> +++ b/net/nfc/nci/core.c
> @@ -70,14 +70,13 @@ int nci_get_conn_info_by_dest_type_params(struct nci_dev *ndev, u8 dest_type,
> struct nci_conn_info *conn_info;
>
> list_for_each_entry(conn_info, &ndev->conn_info_list, list) {

conn_info is set in list_for_each_entry() using container_of(),
which is never NULL. Plus, it is dereferenced there as well.
The check is unnecessary.

Guenter

> - if (conn_info->dest_type == dest_type) {
> + if (conn_info && conn_info->dest_type == dest_type) {
> if (!params)
> return conn_info->conn_id;
> - if (conn_info) {
> - if (params->id == conn_info->dest_params->id &&
> - params->protocol == conn_info->dest_params->protocol)
> - return conn_info->conn_id;
> - }
> +
> + if (params->id == conn_info->dest_params->id &&
> + params->protocol == conn_info->dest_params->protocol)
> + return conn_info->conn_id;
> }
> }
>

2017-06-12 22:53:16

by Gustavo A. R. Silva

Subject: Re: nfc: nci: fix potential NULL pointer dereference

Hi Guenter,

Please, see my comments below

Quoting Guenter Roeck <[email protected]>:

> On Mon, Jun 12, 2017 at 05:02:23PM -0500, Gustavo A. R. Silva wrote:
>> NULL check at line 76: if (conn_info) {, implies that pointer conn_info
>> might be NULL, but this pointer is being previously dereferenced,
>> which might cause a NULL pointer dereference.
>>
>> Add NULL check before dereferencing pointer conn_info in order to
>> avoid a potential NULL pointer dereference.
>>
>> Addresses-Coverity-ID: 1362349
>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>> ---
>> net/nfc/nci/core.c | 11 +++++------
>> 1 file changed, 5 insertions(+), 6 deletions(-)
>>
>> diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
>> index 61fff42..d2198ce 100644
>> --- a/net/nfc/nci/core.c
>> +++ b/net/nfc/nci/core.c
>> @@ -70,14 +70,13 @@ int
>> nci_get_conn_info_by_dest_type_params(struct nci_dev *ndev, u8
>> dest_type,
>> struct nci_conn_info *conn_info;
>>
>> list_for_each_entry(conn_info, &ndev->conn_info_list, list) {
>
> conn_info is set in list_for_each_entry() using container_of(),
> which is never NULL. Plus, it is dereferenced there as well.
> The check is unnecessary.
>

Thanks for clarifying.

> Guenter
>
>> - if (conn_info->dest_type == dest_type) {
>> + if (conn_info && conn_info->dest_type == dest_type) {
>> if (!params)
>> return conn_info->conn_id;
>> - if (conn_info) {

So, this NULL check could be removed as it seems it is not useful at all ?

>> - if (params->id == conn_info->dest_params->id &&
>> - params->protocol == conn_info->dest_params->protocol)
>> - return conn_info->conn_id;
>> - }
>> +
>> + if (params->id == conn_info->dest_params->id &&
>> + params->protocol == conn_info->dest_params->protocol)
>> + return conn_info->conn_id;
>> }
>> }
>>

Thank you
--
Gustavo A. R. Silva

2017-06-13 00:32:01

by Guenter Roeck

Subject: Re: nfc: nci: fix potential NULL pointer dereference

On 06/12/2017 03:28 PM, Gustavo A. R. Silva wrote:
> Hi Guenter,
>
> Please, see my comments below
>
> Quoting Guenter Roeck <[email protected]>:
>
>> On Mon, Jun 12, 2017 at 05:02:23PM -0500, Gustavo A. R. Silva wrote:
>>> NULL check at line 76: if (conn_info) {, implies that pointer conn_info
>>> might be NULL, but this pointer is being previously dereferenced,
>>> which might cause a NULL pointer dereference.
>>>
>>> Add NULL check before dereferencing pointer conn_info in order to
>>> avoid a potential NULL pointer dereference.
>>>
>>> Addresses-Coverity-ID: 1362349
>>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>>> ---
>>> net/nfc/nci/core.c | 11 +++++------
>>> 1 file changed, 5 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
>>> index 61fff42..d2198ce 100644
>>> --- a/net/nfc/nci/core.c
>>> +++ b/net/nfc/nci/core.c
>>> @@ -70,14 +70,13 @@ int nci_get_conn_info_by_dest_type_params(struct nci_dev *ndev, u8 dest_type,
>>> struct nci_conn_info *conn_info;
>>>
>>> list_for_each_entry(conn_info, &ndev->conn_info_list, list) {
>>
>> conn_info is set in list_for_each_entry() using container_of(),
>> which is never NULL. Plus, it is dereferenced there as well.
>> The check is unnecessary.
>>
>
> Thanks for clarifying.
>
>> Guenter
>>
>>> - if (conn_info->dest_type == dest_type) {
>>> + if (conn_info && conn_info->dest_type == dest_type) {
>>> if (!params)
>>> return conn_info->conn_id;
>>> - if (conn_info) {
>
> So, this NULL check could be removed as it seems it is not useful at all ?
>
Exactly.

>>> - if (params->id == conn_info->dest_params->id &&
>>> - params->protocol == conn_info->dest_params->protocol)
>>> - return conn_info->conn_id;
>>> - }
>>> +
>>> + if (params->id == conn_info->dest_params->id &&
>>> + params->protocol == conn_info->dest_params->protocol)
>>> + return conn_info->conn_id;
>>> }
>>> }
>>>
>
> Thank you
> --
> Gustavo A. R. Silva
>
>
>
>
>
>
>

2017-06-13 16:37:24

by Gustavo A. R. Silva

Subject: [PATCH] nfc: nci: remove unnecessary null check

Remove unnecessary NULL check for pointer conn_info.
conn_info is set in list_for_each_entry() using container_of(),
which is never NULL.

Addresses-Coverity-ID: 1362349
Cc: Guenter Roeck <[email protected]>
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
net/nfc/nci/core.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 61fff42..c15cb88 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -73,11 +73,10 @@ int nci_get_conn_info_by_dest_type_params(struct nci_dev *ndev, u8 dest_type,
if (conn_info->dest_type == dest_type) {
if (!params)
return conn_info->conn_id;
- if (conn_info) {
- if (params->id == conn_info->dest_params->id &&
- params->protocol == conn_info->dest_params->protocol)
- return conn_info->conn_id;
- }
+
+ if (params->id == conn_info->dest_params->id &&
+ params->protocol == conn_info->dest_params->protocol)
+ return conn_info->conn_id;
}
}

--
2.5.0

2017-06-15 17:29:09

by Guenter Roeck

Subject: Re: [PATCH] nfc: nci: remove unnecessary null check

On Tue, Jun 13, 2017 at 11:37:18AM -0500, Gustavo A. R. Silva wrote:
> Remove unnecessary NULL check for pointer conn_info.
> conn_info is set in list_for_each_entry() using container_of(),
> which is never NULL.
>
> Addresses-Coverity-ID: 1362349
> Cc: Guenter Roeck <[email protected]>
> Signed-off-by: Gustavo A. R. Silva <[email protected]>

Reviewed-by: Guenter Roeck <[email protected]>

> ---
> net/nfc/nci/core.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
> index 61fff42..c15cb88 100644
> --- a/net/nfc/nci/core.c
> +++ b/net/nfc/nci/core.c
> @@ -73,11 +73,10 @@ int nci_get_conn_info_by_dest_type_params(struct nci_dev *ndev, u8 dest_type,
> if (conn_info->dest_type == dest_type) {
> if (!params)
> return conn_info->conn_id;
> - if (conn_info) {
> - if (params->id == conn_info->dest_params->id &&
> - params->protocol == conn_info->dest_params->protocol)
> - return conn_info->conn_id;
> - }
> +
> + if (params->id == conn_info->dest_params->id &&
> + params->protocol == conn_info->dest_params->protocol)
> + return conn_info->conn_id;
> }
> }
>
> --
> 2.5.0
>

2017-06-22 22:35:34

by Samuel Ortiz

Subject: Re: [PATCH] nfc: nci: remove unnecessary null check

Hi Gustavo,

On Tue, Jun 13, 2017 at 11:37:18AM -0500, Gustavo A. R. Silva wrote:
> Remove unnecessary NULL check for pointer conn_info.
> conn_info is set in list_for_each_entry() using container_of(),
> which is never NULL.
>
> Addresses-Coverity-ID: 1362349
> Cc: Guenter Roeck <[email protected]>
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
> net/nfc/nci/core.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
Applied to nfc-next, thanks.

Cheers,
Samuel.

2017-06-23 01:46:13

by Gustavo A. R. Silva

Subject: Re: [PATCH] nfc: nci: remove unnecessary null check

Hi Samuel,

Quoting Samuel Ortiz <[email protected]>:

> Hi Gustavo,
>
> On Tue, Jun 13, 2017 at 11:37:18AM -0500, Gustavo A. R. Silva wrote:
>> Remove unnecessary NULL check for pointer conn_info.
>> conn_info is set in list_for_each_entry() using container_of(),
>> which is never NULL.
>>
>> Addresses-Coverity-ID: 1362349
>> Cc: Guenter Roeck <[email protected]>
>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>> ---
>> net/nfc/nci/core.c | 9 ++++-----
>> 1 file changed, 4 insertions(+), 5 deletions(-)
> Applied to nfc-next, thanks.
>

Absolutely, glad to help.

Thanks
--
Gustavo A. R. Silva