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

From: Fabio Aiuto
Date: Thu Aug 26 2021 - 13:26:26 EST


Hello Welong,

(Added commit reference)

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
(commit 174ac41a7aafb31041cba3fe54ccd89b9daeef5d)
in staging-testing so maybe rtw_wx_set_scan is going to disappear.

thank you,

fabio