From: Zhao Li Date: Thu, 11 Jun 2026 17:35:07 +0000 (+0800) Subject: wifi: ieee80211: validate MLE common info length X-Git-Tag: v7.2-rc4~17^2~16^2~18 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=293baeae9b2434a3e432629d7720b5603db2d77e;p=thirdparty%2Fkernel%2Flinux.git wifi: ieee80211: validate MLE common info length ieee80211_mle_common_size() uses the first common-info octet as the common information length for all known MLE types. However, ieee80211_mle_size_ok() only validates that octet for Basic, Probe Request, and TDLS MLEs. Reconfiguration MLEs also skipped the length octet when calculating the minimum common size, and Priority Access MLEs skipped validation of the advertised common information length. Account for the Reconfiguration common-info length octet and validate the advertised common information length for all known MLE types. Keep unknown-type handling unchanged. Fixes: 0f48b8b88aa9 ("wifi: ieee80211: add definitions for multi-link element") Cc: stable@vger.kernel.org Signed-off-by: Zhao Li Link: https://patch.msgid.link/20260611173506.36838-2-enderaoelyther@gmail.com [remove now misleading comment] Signed-off-by: Johannes Berg --- diff --git a/include/linux/ieee80211-eht.h b/include/linux/ieee80211-eht.h index 18f9c662cf4c..c109722b1969 100644 --- a/include/linux/ieee80211-eht.h +++ b/include/linux/ieee80211-eht.h @@ -857,7 +857,7 @@ static inline bool ieee80211_mle_size_ok(const u8 *data, size_t len) const struct ieee80211_multi_link_elem *mle = (const void *)data; u8 fixed = sizeof(*mle); u8 common = 0; - bool check_common_len = false; + u8 common_len; u16 control; if (!data || len < fixed) @@ -868,7 +868,6 @@ static inline bool ieee80211_mle_size_ok(const u8 *data, size_t len) switch (u16_get_bits(control, IEEE80211_ML_CONTROL_TYPE)) { case IEEE80211_ML_CONTROL_TYPE_BASIC: common += sizeof(struct ieee80211_mle_basic_common_info); - check_common_len = true; if (control & IEEE80211_MLC_BASIC_PRES_LINK_ID) common += 1; if (control & IEEE80211_MLC_BASIC_PRES_BSS_PARAM_CH_CNT) @@ -888,9 +887,9 @@ static inline bool ieee80211_mle_size_ok(const u8 *data, size_t len) common += sizeof(struct ieee80211_mle_preq_common_info); if (control & IEEE80211_MLC_PREQ_PRES_MLD_ID) common += 1; - check_common_len = true; break; case IEEE80211_ML_CONTROL_TYPE_RECONF: + common += 1; if (control & IEEE80211_MLC_RECONF_PRES_MLD_MAC_ADDR) common += ETH_ALEN; if (control & IEEE80211_MLC_RECONF_PRES_EML_CAPA) @@ -902,7 +901,6 @@ static inline bool ieee80211_mle_size_ok(const u8 *data, size_t len) break; case IEEE80211_ML_CONTROL_TYPE_TDLS: common += sizeof(struct ieee80211_mle_tdls_common_info); - check_common_len = true; break; case IEEE80211_ML_CONTROL_TYPE_PRIO_ACCESS: common = ETH_ALEN + 1; @@ -915,11 +913,9 @@ static inline bool ieee80211_mle_size_ok(const u8 *data, size_t len) if (len < fixed + common) return false; - if (!check_common_len) - return true; + common_len = mle->variable[0]; - /* if present, common length is the first octet there */ - return mle->variable[0] >= common; + return common_len >= common && common_len <= len - fixed; } /**