Re: [PATCH] staging: r8822be: fix null pointer dereference with a null driver_adapter

[Larry Finger]

On 08/23/2017 10:07 AM, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> The call to _rtl_dbg_trace via macro HALMAC_RT_TRACE will trigger a null
> pointer deference on the null driver_adapter.  Fix this by assigning
> driver_adapter earlier to halmac_adapter->driver_adapter before the tracing
> call so that a non-null driver_adapter is passed instead.
>
> Detected by CoverityScan, CID#1454613 ("Explicit null dereferenced")
>
> Fixes: 938a0447f094 ("staging: r8822be: Add code for halmac sub-driver")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>

Acked-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx>

Thanks,

Larry

> ---
>   drivers/staging/rtlwifi/halmac/halmac_88xx/halmac_api_88xx.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/staging/rtlwifi/halmac/halmac_88xx/halmac_api_88xx.c b/drivers/staging/rtlwifi/halmac/halmac_88xx/halmac_api_88xx.c
> index a6c8a87f755f..3a24e33228f8 100644
> --- a/drivers/staging/rtlwifi/halmac/halmac_88xx/halmac_api_88xx.c
> +++ b/drivers/staging/rtlwifi/halmac/halmac_88xx/halmac_api_88xx.c
> @@ -4447,7 +4447,7 @@ halmac_func_p2pps_88xx(struct halmac_adapter *halmac_adapter,
>   {
>   	u8 h2c_buff[HALMAC_H2C_CMD_SIZE_88XX] = {0};
>   	u16 h2c_seq_mum = 0;
> -	void *driver_adapter = NULL;
> +	void *driver_adapter = halmac_adapter->driver_adapter;
>   	struct halmac_api *halmac_api;
>   	struct halmac_h2c_header_info h2c_header_info;
>   	enum halmac_ret_status status = HALMAC_RET_SUCCESS;
> @@ -4455,7 +4455,6 @@ halmac_func_p2pps_88xx(struct halmac_adapter *halmac_adapter,
>   	HALMAC_RT_TRACE(driver_adapter, HALMAC_MSG_H2C, DBG_DMESG,
>   			"[TRACE]halmac_p2pps !!\n");
>   
> -	driver_adapter = halmac_adapter->driver_adapter;
>   	halmac_api = (struct halmac_api *)halmac_adapter->halmac_api;
>   
>   	P2PPS_SET_OFFLOAD_EN(h2c_buff, p2p_ps->offload_en);