Re: [PATCH v2] net: brcm80211: fix missing checks for kmemdup

[Arend Van Spriel]

On 3/12/2019 5:39 AM, Kangjie Lu wrote:
> In case kmemdup fails, the fix sets conn_info->req_ie_len to zero
> to avoid buffer overflows.

Hi Kangjie,

See comment below. Also for v3 change prefix 'net:brcm80211:' to 
'brcmfmac:' instead.

> Signed-off-by: Kangjie Lu <kjlu@xxxxxxx>
> ---
>   drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> index e92f6351bd22..5d9a3c35fef5 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> @@ -5464,6 +5464,8 @@ static s32 brcmf_get_assoc_ies(struct brcmf_cfg80211_info *cfg,
>   		conn_info->req_ie =
>   		    kmemdup(cfg->extra_buf, conn_info->req_ie_len,
>   			    GFP_KERNEL);
> +		if (!conn_info->req_ie)
> +			conn_info->req_ie_len = 0;

good.

>   	} else {
>   		conn_info->req_ie_len = 0;
>   		conn_info->req_ie = NULL;
> @@ -5480,6 +5482,8 @@ static s32 brcmf_get_assoc_ies(struct brcmf_cfg80211_info *cfg,
>   		conn_info->resp_ie =
>   		    kmemdup(cfg->extra_buf, conn_info->resp_ie_len,
>   			    GFP_KERNEL);
> +		if (!conn_info->resp_ie)
> +			conn_info->req_ie_len = 0;

bad! I think you took my comment too literal. Here it should set 
conn_info->resp_ie_len to zero.

Regards,
Arend

>   	} else {
>   		conn_info->resp_ie_len = 0;
>   		conn_info->resp_ie = NULL;