Hello Dmitry,
On Monday 4 December 2023 16:55:37 CET Dmitry Antipov wrote:
>
> Since 'ieee80211_beacon_get()' can return NULL, 'wfx_set_mfp_ap()'
> should check the return value before examining skb data. So convert
> the latter to return an appropriate error code and propagate it to
> return from 'wfx_start_ap()' as well. Compile tested only.
>
> Signed-off-by: Dmitry Antipov <dmantipov@xxxxxxxxx>
> ---
> drivers/net/wireless/silabs/wfx/sta.c | 23 +++++++++++++----------
> 1 file changed, 13 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/net/wireless/silabs/wfx/sta.c b/drivers/net/wireless/silabs/wfx/sta.c
> index 1b6c158457b4..df100d8513ad 100644
> --- a/drivers/net/wireless/silabs/wfx/sta.c
> +++ b/drivers/net/wireless/silabs/wfx/sta.c
> @@ -336,29 +336,35 @@ static int wfx_upload_ap_templates(struct wfx_vif *wvif)
> return 0;
> }
>
> -static void wfx_set_mfp_ap(struct wfx_vif *wvif)
> +static int wfx_set_mfp_ap(struct wfx_vif *wvif)
> {
> struct ieee80211_vif *vif = wvif_to_vif(wvif);
> struct sk_buff *skb = ieee80211_beacon_get(wvif->wdev->hw, vif, 0);
> const int ieoffset = offsetof(struct ieee80211_mgmt, u.beacon.variable);
> - const u16 *ptr = (u16 *)cfg80211_find_ie(WLAN_EID_RSN, skb->data + ieoffset,
> - skb->len - ieoffset);
> const int pairwise_cipher_suite_count_offset = 8 / sizeof(u16);
> const int pairwise_cipher_suite_size = 4 / sizeof(u16);
> const int akm_suite_size = 4 / sizeof(u16);
> + const u16 *ptr;
>
> + if (unlikely(!skb))
> + return -ENOMEM;
> +
> + ptr = (u16 *)cfg80211_find_ie(WLAN_EID_RSN, skb->data + ieoffset,
> + skb->len - ieoffset);
> if (ptr) {
The code would be slightly better if we would invert this condition:
if (!ptr)
return -EINVAL;
> ptr += pairwise_cipher_suite_count_offset;
> if (WARN_ON(ptr > (u16 *)skb_tail_pointer(skb)))
> - return;
> + return -EINVAL;
> ptr += 1 + pairwise_cipher_suite_size * *ptr;
> if (WARN_ON(ptr > (u16 *)skb_tail_pointer(skb)))
> - return;
> + return -EINVAL;
> ptr += 1 + akm_suite_size * *ptr;
> if (WARN_ON(ptr > (u16 *)skb_tail_pointer(skb)))
> - return;
> + return -EINVAL;
> wfx_hif_set_mfp(wvif, *ptr & BIT(7), *ptr & BIT(6));
> + return 0;
> }
> + return -EINVAL;
> }
>
> int wfx_start_ap(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
> @@ -374,10 +380,7 @@ int wfx_start_ap(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
> wvif = (struct wfx_vif *)vif->drv_priv;
> wfx_upload_ap_templates(wvif);
> ret = wfx_hif_start(wvif, &vif->bss_conf, wvif->channel);
> - if (ret > 0)
> - return -EIO;
> - wfx_set_mfp_ap(wvif);
> - return ret;
> + return ret > 0 ? -EIO : wfx_set_mfp_ap(wvif);
I would prefer to not abuse of the trinary operator. I would prefer:
if (ret > 0)
return -EIO;
return wfx_set_mfp_ap(wvif);
> }
>
> void wfx_stop_ap(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
> --
> 2.43.0
>
>
I agree with the patch. Could you fix the cosmetics issues? I will take care
of testing it on real hardware.
--
Jérôme Pouiller
