5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mathy Vanhoef <Mathy.Vanhoef@xxxxxxxxxxx> [ Upstream commit cb17ed29a7a5fea8c9bf70e8a05757d71650e025 ] Already parse the radiotap header in ieee80211_monitor_select_queue. In a subsequent commit this will allow us to add a radiotap flag that influences the queue on which injected packets will be sent. This also fixes the incomplete validation of the injected frame in ieee80211_monitor_select_queue: currently an out of bounds memory access may occur in in the called function ieee80211_select_queue_80211 if the 802.11 header is too small. Note that in ieee80211_monitor_start_xmit the radiotap header is parsed again, which is necessairy because ieee80211_monitor_select_queue is not always called beforehand. Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20200723100153.31631-6-Mathy.Vanhoef@xxxxxxxxxxx Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Stable-dep-of: 9d301de12da6 ("wifi: mac80211: use two-phase skb reclamation in ieee80211_do_stop()") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- include/net/mac80211.h | 8 +++++++ net/mac80211/iface.c | 15 ++++++++---- net/mac80211/tx.c | 54 +++++++++++++++++++----------------------- 3 files changed, 43 insertions(+), 34 deletions(-) diff --git a/include/net/mac80211.h b/include/net/mac80211.h index d9ba9a77bcf29..cf67d7778d3d0 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -6134,6 +6134,14 @@ bool ieee80211_tx_prepare_skb(struct ieee80211_hw *hw, struct ieee80211_vif *vif, struct sk_buff *skb, int band, struct ieee80211_sta **sta); +/** + * Sanity-check and parse the radiotap header of injected frames + * @skb: packet injected by userspace + * @dev: the &struct device of this 802.11 device + */ +bool ieee80211_parse_tx_radiotap(struct sk_buff *skb, + struct net_device *dev); + /** * struct ieee80211_noa_data - holds temporary data for tracking P2P NoA state * diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index ddc001ad90555..1f691180e13db 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -1175,17 +1175,24 @@ static u16 ieee80211_monitor_select_queue(struct net_device *dev, { struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); struct ieee80211_local *local = sdata->local; + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); struct ieee80211_hdr *hdr; - struct ieee80211_radiotap_header *rtap = (void *)skb->data; + int len_rthdr; if (local->hw.queues < IEEE80211_NUM_ACS) return 0; - if (skb->len < 4 || - skb->len < le16_to_cpu(rtap->it_len) + 2 /* frame control */) + /* reset flags and info before parsing radiotap header */ + memset(info, 0, sizeof(*info)); + + if (!ieee80211_parse_tx_radiotap(skb, dev)) return 0; /* doesn't matter, frame will be dropped */ - hdr = (void *)((u8 *)skb->data + le16_to_cpu(rtap->it_len)); + len_rthdr = ieee80211_get_radiotap_len(skb->data); + hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr); + if (skb->len < len_rthdr + 2 || + skb->len < len_rthdr + ieee80211_hdrlen(hdr->frame_control)) + return 0; /* doesn't matter, frame will be dropped */ return ieee80211_select_queue_80211(sdata, skb, hdr); } diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 5fd9a6f752a1d..4afced0588bd4 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -2034,9 +2034,10 @@ void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, ieee80211_tx(sdata, sta, skb, false, txdata_flags); } -static bool ieee80211_parse_tx_radiotap(struct ieee80211_local *local, - struct sk_buff *skb) +bool ieee80211_parse_tx_radiotap(struct sk_buff *skb, + struct net_device *dev) { + struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr); struct ieee80211_radiotap_iterator iterator; struct ieee80211_radiotap_header *rthdr = (struct ieee80211_radiotap_header *) skb->data; @@ -2055,6 +2056,18 @@ static bool ieee80211_parse_tx_radiotap(struct ieee80211_local *local, u8 vht_mcs = 0, vht_nss = 0; int i; + /* check for not even having the fixed radiotap header part */ + if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header))) + return false; /* too short to be possibly valid */ + + /* is it a header version we can trust to find length from? */ + if (unlikely(rthdr->it_version)) + return false; /* only version 0 is supported */ + + /* does the skb contain enough to deliver on the alleged length? */ + if (unlikely(skb->len < ieee80211_get_radiotap_len(skb->data))) + return false; /* skb too short for claimed rt header extent */ + info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT | IEEE80211_TX_CTL_DONTFRAG; @@ -2210,13 +2223,6 @@ static bool ieee80211_parse_tx_radiotap(struct ieee80211_local *local, local->hw.max_rate_tries); } - /* - * remove the radiotap header - * iterator->_max_length was sanity-checked against - * skb->len by iterator init - */ - skb_pull(skb, iterator._max_length); - return true; } @@ -2225,8 +2231,6 @@ netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb, { struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr); struct ieee80211_chanctx_conf *chanctx_conf; - struct ieee80211_radiotap_header *prthdr = - (struct ieee80211_radiotap_header *)skb->data; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); struct ieee80211_hdr *hdr; struct ieee80211_sub_if_data *tmp_sdata, *sdata; @@ -2234,21 +2238,17 @@ netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb, u16 len_rthdr; int hdrlen; - /* check for not even having the fixed radiotap header part */ - if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header))) - goto fail; /* too short to be possibly valid */ + memset(info, 0, sizeof(*info)); + info->flags = IEEE80211_TX_CTL_REQ_TX_STATUS | + IEEE80211_TX_CTL_INJECTED; - /* is it a header version we can trust to find length from? */ - if (unlikely(prthdr->it_version)) - goto fail; /* only version 0 is supported */ + /* Sanity-check and process the injection radiotap header */ + if (!ieee80211_parse_tx_radiotap(skb, dev)) + goto fail; - /* then there must be a radiotap header with a length we can use */ + /* we now know there is a radiotap header with a length we can use */ len_rthdr = ieee80211_get_radiotap_len(skb->data); - /* does the skb contain enough to deliver on the alleged length? */ - if (unlikely(skb->len < len_rthdr)) - goto fail; /* skb too short for claimed rt header extent */ - /* * fix up the pointers accounting for the radiotap * header still being in there. We are being given @@ -2294,11 +2294,6 @@ netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb, skb->priority = *p & IEEE80211_QOS_CTL_TAG1D_MASK; } - memset(info, 0, sizeof(*info)); - - info->flags = IEEE80211_TX_CTL_REQ_TX_STATUS | - IEEE80211_TX_CTL_INJECTED; - rcu_read_lock(); /* @@ -2361,9 +2356,8 @@ netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb, info->band = chandef->chan->band; - /* process and remove the injection radiotap header */ - if (!ieee80211_parse_tx_radiotap(local, skb)) - goto fail_rcu; + /* remove the injection radiotap header */ + skb_pull(skb, len_rthdr); ieee80211_xmit(sdata, NULL, skb, 0); rcu_read_unlock(); -- 2.43.0
