Re: [PATCH] staging: rtl8723bs: fix heap buffer overflow in cfg80211_rtw_add_key

[Luka Gejak]

On Tue Apr 7, 2026 at 12:50 AM CEST, Feng Ning wrote:
> From: Feng Ning <feng@xxxxxxxxx>
> To: gregkh@xxxxxxxxxxxxxxxxxxx
> Cc: linux-staging@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx
> Subject: [PATCH] staging: rtl8723bs: fix heap buffer overflow in cfg80211_rtw_add_key
>
> The cfg80211 framework allows key sequence counters (NL80211_KEY_SEQ)
> up to 16 bytes, but ieee_param.crypt.seq is a fixed 8-byte buffer.
> When cfg80211_rtw_add_key() copies the sequence counter via memcpy()
> without checking seq_len, a heap buffer overflow of up to 8 bytes
> occurs, overwriting adjacent fields key_len and key[].
>
> Cap the copy length at the buffer size using min_t().
>
> Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
> Signed-off-by: Feng Ning <feng@xxxxxxxxx>
> ---
>  drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c b/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c
> index 7cb0c6f22..4fba53c2d 100644
> --- a/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c
> +++ b/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c
> @@ -883,8 +883,11 @@ static int cfg80211_rtw_add_key(struct wiphy *wiphy, struct net_device *ndev,
>  
>  	param->u.crypt.idx = key_index;
>  
> -	if (params->seq_len && params->seq)
> -		memcpy(param->u.crypt.seq, (u8 *)params->seq, params->seq_len);
> +	if (params->seq_len && params->seq) {
> +		size_t seq_copy = min_t(size_t, params->seq_len,
> +				       sizeof(param->u.crypt.seq));
> +		memcpy(param->u.crypt.seq, (u8 *)params->seq, seq_copy);
> +	}
>  
>  	if (params->key_len && params->key) {
>  		param->u.crypt.key_len = params->key_len;

Hi Feng,
one quick question, why did you send same patch as before? If it is 
because it hasn't been merged yet please wait because it is currently 
merge window and we are not accepting any new patches. We will come to 
your patch eventually, just be patient.
Best regards,
Luka Gejak