Re: [PATCH v2] staging: rtl8723bs: fix heap buffer overflow in cfg80211_rtw_add_key

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Apr 07, 2026 at 10:21:18AM +0000, Feng Ning wrote:
> 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@innora.ai>
> ---
>  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.c
> rypt.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;
> -- 
> 2.43.0




Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
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thanks,

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