diff options
| author | Felix Fietkau <nbd@openwrt.org> | 2012-09-08 11:58:30 +0200 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2012-09-10 18:44:58 +0200 |
| commit | 1bad53824305807bb5cf49d6b588dd9d867586c6 (patch) | |
| tree | 55f046a4d3c0eec4f2f16b18b586c5e245921a03 /net | |
| parent | mac80211: use call_rcu() on sta deletion (diff) | |
| download | linux-1bad53824305807bb5cf49d6b588dd9d867586c6.tar.xz linux-1bad53824305807bb5cf49d6b588dd9d867586c6.zip | |
mac80211: validate skb->dev in the tx status path
skb->dev might contain a stale reference to a device that was already
deleted, and using it unchecked can lead to invalid pointer accesses.
Since this is only used for nl80211 tx, iterate over active interfaces
to find a match for skb->dev, and discard the tx status if the device
is gone.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/mac80211/status.c | 48 |
1 files changed, 30 insertions, 18 deletions
diff --git a/net/mac80211/status.c b/net/mac80211/status.c index b0801b7d572d..2ce89732d0f2 100644 --- a/net/mac80211/status.c +++ b/net/mac80211/status.c @@ -517,29 +517,41 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb) if (info->flags & IEEE80211_TX_INTFL_NL80211_FRAME_TX) { u64 cookie = (unsigned long)skb; + bool found = false; + acked = info->flags & IEEE80211_TX_STAT_ACK; - if (ieee80211_is_nullfunc(hdr->frame_control) || - ieee80211_is_qos_nullfunc(hdr->frame_control)) { - cfg80211_probe_status(skb->dev, hdr->addr1, - cookie, acked, GFP_ATOMIC); - } else if (skb->dev) { - cfg80211_mgmt_tx_status( - skb->dev->ieee80211_ptr, cookie, skb->data, - skb->len, acked, GFP_ATOMIC); - } else { - struct ieee80211_sub_if_data *p2p_sdata; + rcu_read_lock(); + + list_for_each_entry_rcu(sdata, &local->interfaces, list) { + if (!sdata->dev) + continue; - rcu_read_lock(); + if (skb->dev != sdata->dev) + continue; - p2p_sdata = rcu_dereference(local->p2p_sdata); - if (p2p_sdata) { - cfg80211_mgmt_tx_status( - &p2p_sdata->wdev, cookie, skb->data, - skb->len, acked, GFP_ATOMIC); - } - rcu_read_unlock(); + found = true; + break; + } + + if (!skb->dev) { + sdata = rcu_dereference(local->p2p_sdata); + if (sdata) + found = true; + } + + if (!found) + skb->dev = NULL; + else if (ieee80211_is_nullfunc(hdr->frame_control) || + ieee80211_is_qos_nullfunc(hdr->frame_control)) { + cfg80211_probe_status(sdata->dev, hdr->addr1, + cookie, acked, GFP_ATOMIC); + } else { + cfg80211_mgmt_tx_status(&sdata->wdev, cookie, skb->data, + skb->len, acked, GFP_ATOMIC); } + + rcu_read_unlock(); } if (unlikely(info->ack_frame_id)) { |