Re: [PATCH] staging: wicl1000: fix dereference after free in wilc_wlan_cleanup()

2015-09-22 Thread Sudip Mukherjee
On Tue, Sep 22, 2015 at 12:24:50PM +0200, Javier Martinez Canillas wrote:
> The wilc_wlan_cleanup() function iterates over the list of transmission
> buffers freeing all of them and then iterates over the receive buffers
> list to free all of them as well.
> 
> But on the receive loop a pointer to struct txq_entry_t is dereferenced
> instead of the pointer to a struct rxq_entry_t. This not only causes a
> dereference to a pointer already freed but also leaks the memory in the
> struct rxq_entry_t buffer.
> 
> Fixes: c5c77ba18ea6 ("staging: wilc1000: Add SDIO/SPI 802.11 driver")
> Signed-off-by: Javier Martinez Canillas 
> 
> ---
> 
>  drivers/staging/wilc1000/wilc_wlan.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/wilc1000/wilc_wlan.c 
> b/drivers/staging/wilc1000/wilc_wlan.c
> index 4c25179c2fec..c40f143b00b7 100644
> --- a/drivers/staging/wilc1000/wilc_wlan.c
> +++ b/drivers/staging/wilc1000/wilc_wlan.c
> @@ -1746,7 +1746,7 @@ static void wilc_wlan_cleanup(void)
>   if (rqe == NULL)
>   break;
>  #ifdef MEMORY_DYNAMIC
> - kfree(tqe->buffer);
> + kfree(rqe->buffer);
>  #endif
MEMORY_DYNAMIC is only used here and no where else. And buffer was
allocated in the else part of #ifdef MEMORY_STATIC.
So you should really be using #ifndef MEMORY_STATIC here instead of
#ifdef MEMORY_DYNAMIC otherwise memory leak will still remain.

regards
sudip
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Re: [PATCH] staging: wicl1000: fix dereference after free in wilc_wlan_cleanup()

2015-09-22 Thread Javier Martinez Canillas
Hello Sudip,

Thanks a lot for your feedback.

On 09/22/2015 02:16 PM, Sudip Mukherjee wrote:
> On Tue, Sep 22, 2015 at 12:24:50PM +0200, Javier Martinez Canillas wrote:
>> The wilc_wlan_cleanup() function iterates over the list of transmission
>> buffers freeing all of them and then iterates over the receive buffers
>> list to free all of them as well.
>>
>> But on the receive loop a pointer to struct txq_entry_t is dereferenced
>> instead of the pointer to a struct rxq_entry_t. This not only causes a
>> dereference to a pointer already freed but also leaks the memory in the
>> struct rxq_entry_t buffer.
>>
>> Fixes: c5c77ba18ea6 ("staging: wilc1000: Add SDIO/SPI 802.11 driver")
>> Signed-off-by: Javier Martinez Canillas 
>>
>> ---
>>
>>  drivers/staging/wilc1000/wilc_wlan.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/staging/wilc1000/wilc_wlan.c 
>> b/drivers/staging/wilc1000/wilc_wlan.c
>> index 4c25179c2fec..c40f143b00b7 100644
>> --- a/drivers/staging/wilc1000/wilc_wlan.c
>> +++ b/drivers/staging/wilc1000/wilc_wlan.c
>> @@ -1746,7 +1746,7 @@ static void wilc_wlan_cleanup(void)
>>  if (rqe == NULL)
>>  break;
>>  #ifdef MEMORY_DYNAMIC
>> -kfree(tqe->buffer);
>> +kfree(rqe->buffer);
>>  #endif
> MEMORY_DYNAMIC is only used here and no where else. And buffer was
> allocated in the else part of #ifdef MEMORY_STATIC.
> So you should really be using #ifndef MEMORY_STATIC here instead of
> #ifdef MEMORY_DYNAMIC otherwise memory leak will still remain.
>

You are right that #ifndef MEMORY_STATIC should be used instead to fix
the memory leak. I'll post a v2 changing that as well.

> regards
> sudip
>

Best regards,
-- 
Javier Martinez Canillas
Open Source Group
Samsung Research America
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