From 59651e89187293e88863891b821c7379391ef75c Mon Sep 17 00:00:00 2001 From: Christian Lamparter Date: Tue, 9 Dec 2008 21:07:50 +0100 Subject: [PATCH] p54: fix oops on faulty devices This patch fixes an oops when the devices suddenly starts to receive martian data frames. bug reference: http://marc.info/?l=linux-wireless&m=122872280317635&w=2 Signed-off-by: Christian Lamparter Signed-off-by: John W. Linville --- drivers/net/wireless/p54/p54common.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/p54/p54common.c b/drivers/net/wireless/p54/p54common.c index fac6b416e9e9..a4e99b02af02 100644 --- a/drivers/net/wireless/p54/p54common.c +++ b/drivers/net/wireless/p54/p54common.c @@ -540,6 +540,14 @@ static int p54_rx_data(struct ieee80211_hw *dev, struct sk_buff *skb) size_t header_len = sizeof(*hdr); u32 tsf32; + /* + * If the device is in a unspecified state we have to + * ignore all data frames. Else we could end up with a + * nasty crash. + */ + if (unlikely(priv->mode == NL80211_IFTYPE_UNSPECIFIED)) + return 0; + if (!(hdr->flags & cpu_to_le16(P54_HDR_FLAG_DATA_IN_FCS_GOOD))) { if (priv->filter_flags & FIF_FCSFAIL) rx_status.flag |= RX_FLAG_FAILED_FCS_CRC; @@ -608,6 +616,12 @@ void p54_free_skb(struct ieee80211_hw *dev, struct sk_buff *skb) if (unlikely(!skb || !dev || !skb_queue_len(&priv->tx_queue))) return; + /* + * don't try to free an already unlinked skb + */ + if (unlikely((!skb->next) || (!skb->prev))) + return; + spin_lock_irqsave(&priv->tx_queue.lock, flags); info = IEEE80211_SKB_CB(skb); range = (void *)info->rate_driver_data; @@ -1695,19 +1709,18 @@ static void p54_stop(struct ieee80211_hw *dev) struct sk_buff *skb; mutex_lock(&priv->conf_mutex); + priv->mode = NL80211_IFTYPE_UNSPECIFIED; del_timer(&priv->stats_timer); p54_free_skb(dev, priv->cached_stats); priv->cached_stats = NULL; if (priv->cached_beacon) p54_tx_cancel(dev, priv->cached_beacon); + priv->stop(dev); while ((skb = skb_dequeue(&priv->tx_queue))) kfree_skb(skb); - priv->cached_beacon = NULL; - priv->stop(dev); priv->tsf_high32 = priv->tsf_low32 = 0; - priv->mode = NL80211_IFTYPE_UNSPECIFIED; mutex_unlock(&priv->conf_mutex); } -- 2.20.1