[PATCH 6.1 067/219] wifi: wfx: fix possible NULL pointer dereference in wfx_set_mfp_ap()

Greg Kroah-Hartman
2024-02-03T04:09:28Z

From: Dmitry Antipov <dmantipov@yandex.ru>

[ Upstream commit fe0a7776d4d19e613bb8dd80fe2d78ae49e8b49d ]

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@yandex.ru>
Tested-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Acked-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20231204171130.141394-1-dmantipov@yandex.ru
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/silabs/wfx/sta.c | 42 ++++++++++++++++-----------
1 file changed, 25 insertions(+), 17 deletions(-)

diff --git a/drivers/net/wireless/silabs/wfx/sta.c b/drivers/net/wireless/silabs/wfx/sta.c
index 626dfb4b7a55..073e870b2641 100644
--- a/drivers/net/wireless/silabs/wfx/sta.c
+++ b/drivers/net/wireless/silabs/wfx/sta.c
@@ -354,29 +354,38 @@ 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 (ptr) {
- ptr += pairwise_cipher_suite_count_offset;
- if (WARN_ON(ptr > (u16 *)skb_tail_pointer(skb)))
- return;
- ptr += 1 + pairwise_cipher_suite_size * *ptr;
- if (WARN_ON(ptr > (u16 *)skb_tail_pointer(skb)))
- return;
- ptr += 1 + akm_suite_size * *ptr;
- if (WARN_ON(ptr > (u16 *)skb_tail_pointer(skb)))
- return;
- wfx_hif_set_mfp(wvif, *ptr & BIT(7), *ptr & BIT(6));
- }
+ if (unlikely(!skb))
+ return -ENOMEM;
+
+ ptr = (u16 *)cfg80211_find_ie(WLAN_EID_RSN, skb->data + ieoffset,
+ skb->len - ieoffset);
+ if (unlikely(!ptr))
+ return -EINVAL;
+
+ ptr += pairwise_cipher_suite_count_offset;
+ if (WARN_ON(ptr > (u16 *)skb_tail_pointer(skb)))
+ return -EINVAL;
+
+ ptr += 1 + pairwise_cipher_suite_size * *ptr;
+ if (WARN_ON(ptr > (u16 *)skb_tail_pointer(skb)))
+ return -EINVAL;
+
+ ptr += 1 + akm_suite_size * *ptr;
+ if (WARN_ON(ptr > (u16 *)skb_tail_pointer(skb)))
+ 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,
@@ -394,8 +403,7 @@ 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,
--
2.43.0