cfg80211_rx_mlme_mgmt() and cfg80211_tx_mlme_mgmt() read the frame control field without first checking len >= 2, then dispatch into subtype handlers that assume their fixed fields are present. Add a frame-control length gate, then validate each subtype's minimum frame size in an if/else-if chain that mirrors the dispatch logic. Trace only after the frame is known to be well-formed. Side effects of this change: - The WARN_ON(len < 2) is replaced by a silent early return, since these cfg80211 callbacks can legitimately receive short frames from drivers. - cfg80211_tx_mlme_mgmt() previously routed every non-deauth subtype through disassociation handling; it now silently ignores unrecognised subtypes. Assisted-by: Codex:gpt-5.5 Assisted-by: Claude:claude-opus-4.8 Signed-off-by: Zhao Li --- net/wireless/mlme.c | 45 +++++++++++++++++++++++++++++++++++++-------- 1 file changed, 37 insertions(+), 8 deletions(-) diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c index bd72317c4964e..a0f7b08bfcc9c 100644 --- a/net/wireless/mlme.c +++ b/net/wireless/mlme.c @@ -150,19 +150,35 @@ void cfg80211_rx_mlme_mgmt(struct net_device *dev, const u8 *buf, size_t len) { struct wireless_dev *wdev = dev->ieee80211_ptr; struct ieee80211_mgmt *mgmt = (void *)buf; + __le16 fc; lockdep_assert_wiphy(wdev->wiphy); - trace_cfg80211_rx_mlme_mgmt(dev, buf, len); + if (len < sizeof(fc)) + return; + + fc = mgmt->frame_control; - if (WARN_ON(len < 2)) + if (ieee80211_is_auth(fc)) { + if (len < offsetofend(struct ieee80211_mgmt, u.auth.status_code)) + return; + } else if (ieee80211_is_deauth(fc)) { + if (len < offsetofend(struct ieee80211_mgmt, u.deauth.reason_code)) + return; + } else if (ieee80211_is_disassoc(fc)) { + if (len < offsetofend(struct ieee80211_mgmt, u.disassoc.reason_code)) + return; + } else { return; + } + + trace_cfg80211_rx_mlme_mgmt(dev, buf, len); - if (ieee80211_is_auth(mgmt->frame_control)) + if (ieee80211_is_auth(fc)) cfg80211_process_auth(wdev, buf, len); - else if (ieee80211_is_deauth(mgmt->frame_control)) + else if (ieee80211_is_deauth(fc)) cfg80211_process_deauth(wdev, buf, len, false); - else if (ieee80211_is_disassoc(mgmt->frame_control)) + else cfg80211_process_disassoc(wdev, buf, len, false); } EXPORT_SYMBOL(cfg80211_rx_mlme_mgmt); @@ -215,15 +231,28 @@ void cfg80211_tx_mlme_mgmt(struct net_device *dev, const u8 *buf, size_t len, { struct wireless_dev *wdev = dev->ieee80211_ptr; struct ieee80211_mgmt *mgmt = (void *)buf; + __le16 fc; lockdep_assert_wiphy(wdev->wiphy); - trace_cfg80211_tx_mlme_mgmt(dev, buf, len, reconnect); + if (len < sizeof(fc)) + return; - if (WARN_ON(len < 2)) + fc = mgmt->frame_control; + + if (ieee80211_is_deauth(fc)) { + if (len < offsetofend(struct ieee80211_mgmt, u.deauth.reason_code)) + return; + } else if (ieee80211_is_disassoc(fc)) { + if (len < offsetofend(struct ieee80211_mgmt, u.disassoc.reason_code)) + return; + } else { return; + } + + trace_cfg80211_tx_mlme_mgmt(dev, buf, len, reconnect); - if (ieee80211_is_deauth(mgmt->frame_control)) + if (ieee80211_is_deauth(fc)) cfg80211_process_deauth(wdev, buf, len, reconnect); else cfg80211_process_disassoc(wdev, buf, len, reconnect); -- 2.50.1 (Apple Git-155)