From d8ca16db6bb23d03fcb794df44bae64ae976f27c Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 23 Jan 2014 16:20:29 +0100 Subject: mac80211: add length check in ieee80211_is_robust_mgmt_frame() A few places weren't checking that the frame passed to the function actually has enough data even though the function clearly documents it must have a payload byte. Make this safer by changing the function to take an skb and checking the length inside. The old version is preserved for now as the rtl* drivers use it and don't have a correct skb. Signed-off-by: Johannes Berg --- net/mac80211/rx.c | 13 ++++++------- net/mac80211/tx.c | 9 ++++----- net/mac80211/wpa.c | 2 +- 3 files changed, 11 insertions(+), 13 deletions(-) (limited to 'net') diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index c24ca0d0f469..3b7a750ebc70 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -599,10 +599,10 @@ static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; - if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1)) + if (is_multicast_ether_addr(hdr->addr1)) return 0; - return ieee80211_is_robust_mgmt_frame(hdr); + return ieee80211_is_robust_mgmt_frame(skb); } @@ -610,10 +610,10 @@ static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; - if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1)) + if (!is_multicast_ether_addr(hdr->addr1)) return 0; - return ieee80211_is_robust_mgmt_frame(hdr); + return ieee80211_is_robust_mgmt_frame(skb); } @@ -626,7 +626,7 @@ static int ieee80211_get_mmie_keyidx(struct sk_buff *skb) if (skb->len < 24 + sizeof(*mmie) || !is_multicast_ether_addr(hdr->da)) return -1; - if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr)) + if (!ieee80211_is_robust_mgmt_frame(skb)) return -1; /* not a robust management frame */ mmie = (struct ieee80211_mmie *) @@ -1845,8 +1845,7 @@ static int ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx) * having configured keys. */ if (unlikely(ieee80211_is_action(fc) && !rx->key && - ieee80211_is_robust_mgmt_frame( - (struct ieee80211_hdr *) rx->skb->data))) + ieee80211_is_robust_mgmt_frame(rx->skb))) return -EACCES; } diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index bb990ecfa655..07a7f38dc348 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -452,8 +452,7 @@ static int ieee80211_use_mfp(__le16 fc, struct sta_info *sta, if (sta == NULL || !test_sta_flag(sta, WLAN_STA_MFP)) return 0; - if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) - skb->data)) + if (!ieee80211_is_robust_mgmt_frame(skb)) return 0; return 1; @@ -567,7 +566,7 @@ ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx) tx->key = key; else if (ieee80211_is_mgmt(hdr->frame_control) && is_multicast_ether_addr(hdr->addr1) && - ieee80211_is_robust_mgmt_frame(hdr) && + ieee80211_is_robust_mgmt_frame(tx->skb) && (key = rcu_dereference(tx->sdata->default_mgmt_key))) tx->key = key; else if (is_multicast_ether_addr(hdr->addr1) && @@ -582,12 +581,12 @@ ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx) tx->key = NULL; else if (tx->skb->protocol == tx->sdata->control_port_protocol) tx->key = NULL; - else if (ieee80211_is_robust_mgmt_frame(hdr) && + else if (ieee80211_is_robust_mgmt_frame(tx->skb) && !(ieee80211_is_action(hdr->frame_control) && tx->sta && test_sta_flag(tx->sta, WLAN_STA_MFP))) tx->key = NULL; else if (ieee80211_is_mgmt(hdr->frame_control) && - !ieee80211_is_robust_mgmt_frame(hdr)) + !ieee80211_is_robust_mgmt_frame(tx->skb)) tx->key = NULL; else { I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted); diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c index 4aed45c8ee3b..b8600e3c29c8 100644 --- a/net/mac80211/wpa.c +++ b/net/mac80211/wpa.c @@ -494,7 +494,7 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx) hdrlen = ieee80211_hdrlen(hdr->frame_control); if (!ieee80211_is_data(hdr->frame_control) && - !ieee80211_is_robust_mgmt_frame(hdr)) + !ieee80211_is_robust_mgmt_frame(skb)) return RX_CONTINUE; data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - -- cgit v1.2.3