Re: [PATCH] wifi: mt76: Fix NULL Pointer Dereference caused by mt76_connac_get_he_phy_cap()

[Krzysztof Kozlowski <krzk@kernel.org>]

On 30/09/2024 23:20, Gax-c wrote:
> like commit f503ae90c735 ("wifi: mt76: mt7996: fix NULL pointer dereference in mt7996_mcu_sta_bfer_he"), mt76_connac_get_he_phy_cap() may return a NULL pointer, leading to NULL Pointer Dereference.
> Add a null check for the returned pointer.
> 
> Fixes: a5c372f77aa7 ("wifi: mt76: mt7925: extend mt7925_mcu_bss_he_tlv for per-link BSS")
> Fixes: e6d557a78b60 ("mt76: mt7915: rely on mt76_connac_get_phy utilities")
> Fixes: 98686cd21624 ("wifi: mt76: mt7996: add driver for MediaTek Wi-Fi 7 (802.11be) devices")
> Signed-off-by: Zichen Xie <zichenxie0106@gmail.com>
> Reported-by: Zichen Xie <zichenxie0106@gmail.com>
> Reported-by: Zijie Zhao <zzjas98@gmail.com>
> Reported-by: Chenyuan Yang <chenyuan0y@gmail.com>

Same comments as in other patches.

> ---
>  drivers/net/wireless/mediatek/mt76/mt7915/mcu.c | 6 ++++++
>  drivers/net/wireless/mediatek/mt76/mt7925/mcu.c | 3 +++
>  drivers/net/wireless/mediatek/mt76/mt7996/mcu.c | 3 +++
>  3 files changed, 12 insertions(+)
> 
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
> index 87d0dd040001..941a6e40e94c 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
> @@ -552,6 +552,9 @@ mt7915_mcu_bss_he_tlv(struct sk_buff *skb, struct ieee80211_vif *vif,
>  
>  	cap = mt76_connac_get_he_phy_cap(phy->mt76, vif);
>  

Same problem as in other patches - drop unnecessary blank line.

> +	if (!cap)
> +		return;
> +
>  	tlv = mt76_connac_mcu_add_tlv(skb, BSS_INFO_HE_BASIC, sizeof(*he));
>  
>  	he = (struct bss_info_he *)tlv;
> @@ -1145,6 +1148,9 @@ mt7915_mcu_sta_bfer_he(struct ieee80211_sta *sta, struct ieee80211_vif *vif,
>  	u8 nss_mcs = mt7915_mcu_get_sta_nss(mcs_map);
>  	u8 snd_dim, sts;
>  
> +	if (!vc)
> +		return;
> +
>  	bf->tx_mode = MT_PHY_TYPE_HE_SU;
>  
>  	mt7915_mcu_sta_sounding_rate(bf);
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7925/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7925/mcu.c
> index 748ea6adbc6b..1caf3e3e0e87 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7925/mcu.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7925/mcu.c
> @@ -2509,6 +2509,9 @@ mt7925_mcu_bss_he_tlv(struct sk_buff *skb, struct ieee80211_bss_conf *link_conf,
>  
>  	cap = mt76_connac_get_he_phy_cap(phy->mt76, link_conf->vif);
>  
> +	if (!cap)
> +		return;
> +
>  	tlv = mt76_connac_mcu_add_tlv(skb, UNI_BSS_INFO_HE_BASIC, sizeof(*he));
>  
>  	he = (struct bss_info_uni_he *)tlv;
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
> index 6c445a9dbc03..e547729701b7 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
> @@ -799,6 +799,9 @@ mt7996_mcu_bss_he_tlv(struct sk_buff *skb, struct ieee80211_vif *vif,
>  
>  	cap = mt76_connac_get_he_phy_cap(phy->mt76, vif);
>  
> +	if (!cap)
> +		return;

Don't you need to handle the error? Cleanup?


Best regards,
Krzysztof