Commit fe0a7776 authored by Dmitry Antipov's avatar Dmitry Antipov Committed by Kalle Valo
Browse files

wifi: wfx: fix possible NULL pointer dereference in wfx_set_mfp_ap() 



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: default avatarDmitry Antipov <dmantipov@yandex.ru>
Tested-by: default avatarJérôme Pouiller <jerome.pouiller@silabs.com>
Acked-by: default avatarJérôme Pouiller <jerome.pouiller@silabs.com>
Signed-off-by: default avatarKalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20231204171130.141394-1-dmantipov@yandex.ru
parent 595b1280

drivers/net/wireless/silabs/wfx/sta.c

+25 −17
Original line number Diff line number Diff line
@@ -336,29 +336,38 @@ 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 (unlikely(!ptr))

		return -EINVAL;



	if (ptr) {

	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;

}



int wfx_start_ap(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
@@ -376,8 +385,7 @@ int wfx_start_ap(struct ieee80211_hw *hw, struct ieee80211_vif *vif, 
	ret = wfx_hif_start(wvif, &vif->bss_conf, wvif->channel);

	if (ret > 0)

		return -EIO;

	wfx_set_mfp_ap(wvif);

	return ret;

	return wfx_set_mfp_ap(wvif);

}



void wfx_stop_ap(struct ieee80211_hw *hw, struct ieee80211_vif *vif,