Re: [PATCH] staging: rtl8723bs: prevent ->ssid overflow in rtw_wx_set_scan()

[Fabio Aiuto]

Hello Welong,

On Thu, Aug 26, 2021 at 11:46:22PM +0800, Wenlong Zhang wrote:
> Commit 74b6b20df8cf ("staging: rtl8188eu: prevent ->ssid overflow in rtw_wx_set_scan()")
> fixed up the staging driver rtl8188eu by adding another check 
> to prevent writing beyond the end of the ->ssid[] array.
> 
> Resolve this by properly fixing up the rtl8723bs driver's version of
> rtw_wx_set_scan() 
> 
> Reported-by: Wenlong Zhang(iLifetruth) <yixiaonn@xxxxxxxxx>
> Fixes: 74b6b20df8cf ("staging: rtl8188eu: prevent ->ssid overflow in rtw_wx_set_scan()")
> 
> Signed-off-by: Wenlong Zhang <yixiaonn@xxxxxxxxx>
> 
> ---
>  drivers/staging/rtl8723bs/os_dep/ioctl_linux.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/rtl8723bs/os_dep/ioctl_linux.c b/drivers/staging/rtl8723bs/os_dep/ioctl_linux.c
> index 902ac8169948..6fc1020cea11 100644
> --- a/drivers/staging/rtl8723bs/os_dep/ioctl_linux.c
> +++ b/drivers/staging/rtl8723bs/os_dep/ioctl_linux.c
> @@ -1351,9 +1351,9 @@ static int rtw_wx_set_scan(struct net_device *dev, struct iw_request_info *a,
>  
>  					sec_len = *(pos++); len -= 1;
>  
> -					if (sec_len > 0 && sec_len <= len) {
> +					if (sec_len > 0 && sec_len <= len && sec_len <= 32) {
>  						ssid[ssid_index].SsidLength = sec_len;
> -						memcpy(ssid[ssid_index].Ssid, pos, ssid[ssid_index].SsidLength);
> +						memcpy(ssid[ssid_index].Ssid, pos, sec_len);
>  						/* DBG_871X("%s COMBO_SCAN with specific ssid:%s, %d\n", __func__ */
>  						/* 	, ssid[ssid_index].Ssid, ssid[ssid_index].SsidLength); */
>  						ssid_index++;
> -- 
> 2.15.0
> 

today the patch which removes wext handlers has been accepted
in staging-testing so maybe rtw_wx_set_scan is going to disappear.

thank you,

fabio