From 77001c1bcf5d7d32b1784e9fb7bd7b587595d630 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Mon, 14 Feb 2022 17:29:21 +0100 Subject: [PATCH] ieee80211: add helper to check HE capability element size This element has a very dynamic structure, create a small helper function to validate its size. We're currently checking it in mac80211 in a conversion function, but that's actually slightly buggy. Link: https://lore.kernel.org/r/20220214172920.750bee9eaf37.Ie18359bd38143b7dc949078f10752413e6d36854@changeid Signed-off-by: Johannes Berg Signed-off-by: Christian Lamparter --- include/linux/ieee80211.h | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h index 60b16bd..896977e 100644 --- a/include/linux/ieee80211.h +++ b/include/linux/ieee80211.h @@ -9,7 +9,7 @@ * Copyright (c) 2006, Michael Wu * Copyright (c) 2013 - 2014 Intel Mobile Communications GmbH * Copyright (c) 2016 - 2017 Intel Deutschland GmbH - * Copyright (c) 2018 - 2021 Intel Corporation + * Copyright (c) 2018 - 2022 Intel Corporation */ #ifndef __LINUX_IEEE80211_H @@ -2357,6 +2357,29 @@ ieee80211_he_ppe_size(u8 ppe_thres_hdr, const u8 *phy_cap_info) return n; } +static inline bool ieee80211_he_capa_size_ok(const u8 *data, u8 len) +{ + const struct ieee80211_he_cap_elem *he_cap_ie_elem = (const void *)data; + u8 needed = sizeof(*he_cap_ie_elem); + + if (len < needed) + return false; + + needed += ieee80211_he_mcs_nss_size(he_cap_ie_elem); + if (len < needed) + return false; + + if (he_cap_ie_elem->phy_cap_info[6] & + IEEE80211_HE_PHY_CAP6_PPE_THRESHOLD_PRESENT) { + if (len < needed + 1) + return false; + needed += ieee80211_he_ppe_size(data[needed], + he_cap_ie_elem->phy_cap_info); + } + + return len >= needed; +} + /* HE Operation defines */ #define IEEE80211_HE_OPERATION_DFLT_PE_DURATION_MASK 0x00000007 #define IEEE80211_HE_OPERATION_TWT_REQUIRED 0x00000008 -- 2.31.1