From: Benjamin Berg Date: Thu, 29 Jan 2026 10:33:50 +0000 (+0100) Subject: wifi: mac80211: correctly decode TTLM with default link map X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1eab33aa63c993685dd341e03bd5b267dd7403fa;p=thirdparty%2Fkernel%2Flinux.git wifi: mac80211: correctly decode TTLM with default link map TID-To-Link Mapping (TTLM) elements do not contain any link mapping presence indicator if a default mapping is used and parsing needs to be skipped. Note that access points should not explicitly report an advertised TTLM with a default mapping as that is the implied mapping if the element is not included, this is even the case when switching back to the default mapping. However, mac80211 would incorrectly parse the frame and would also read one byte beyond the end of the element. Reported-by: Ruikai Peng Closes: https://lore.kernel.org/linux-wireless/CAFD3drMqc9YWvTCSHLyP89AOpBZsHdZ+pak6zVftYoZcUyF7gw@mail.gmail.com Fixes: 702e80470a33 ("wifi: mac80211: support handling of advertised TID-to-link mapping") Signed-off-by: Benjamin Berg Link: https://patch.msgid.link/20260129113349.d6b96f12c732.I69212a50f0f70db185edd3abefb6f04d3cb3e5ff@changeid Signed-off-by: Johannes Berg --- diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index b72345c779c0..73f57b9e0ebf 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -8,7 +8,7 @@ * Copyright 2007, Michael Wu * Copyright 2013-2014 Intel Mobile Communications GmbH * Copyright (C) 2015 - 2017 Intel Deutschland GmbH - * Copyright (C) 2018 - 2025 Intel Corporation + * Copyright (C) 2018 - 2026 Intel Corporation */ #include @@ -6190,8 +6190,10 @@ ieee80211_parse_adv_t2l(struct ieee80211_sub_if_data *sdata, return -EINVAL; } - link_map_presence = *pos; - pos++; + if (!(control & IEEE80211_TTLM_CONTROL_DEF_LINK_MAP)) { + link_map_presence = *pos; + pos++; + } if (control & IEEE80211_TTLM_CONTROL_SWITCH_TIME_PRESENT) { ttlm_info->switch_time = get_unaligned_le16(pos);