p54: fix race condition in memory management
This patch fixes a number of race conditions in the driver.
Up until now, "entry" pointer was initialized before acquiring the right lock.
Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/p54/p54common.c b/drivers/net/wireless/p54/p54common.c
index 34561e6..f170106 100644
--- a/drivers/net/wireless/p54/p54common.c
+++ b/drivers/net/wireless/p54/p54common.c
@@ -710,10 +710,11 @@
__le32 req_id)
{
struct p54_common *priv = dev->priv;
- struct sk_buff *entry = priv->tx_queue.next;
+ struct sk_buff *entry;
unsigned long flags;
spin_lock_irqsave(&priv->tx_queue.lock, flags);
+ entry = priv->tx_queue.next;
while (entry != (struct sk_buff *)&priv->tx_queue) {
struct p54_hdr *hdr = (struct p54_hdr *) entry->data;
@@ -732,7 +733,7 @@
struct p54_common *priv = dev->priv;
struct p54_hdr *hdr = (struct p54_hdr *) skb->data;
struct p54_frame_sent *payload = (struct p54_frame_sent *) hdr->data;
- struct sk_buff *entry = (struct sk_buff *) priv->tx_queue.next;
+ struct sk_buff *entry;
u32 addr = le32_to_cpu(hdr->req_id) - priv->headroom;
struct memrecord *range = NULL;
u32 freed = 0;
@@ -741,6 +742,7 @@
int count, idx;
spin_lock_irqsave(&priv->tx_queue.lock, flags);
+ entry = (struct sk_buff *) priv->tx_queue.next;
while (entry != (struct sk_buff *)&priv->tx_queue) {
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(entry);
struct p54_hdr *entry_hdr;
@@ -976,7 +978,7 @@
struct p54_hdr *data, u32 len)
{
struct p54_common *priv = dev->priv;
- struct sk_buff *entry = priv->tx_queue.next;
+ struct sk_buff *entry;
struct sk_buff *target_skb = NULL;
struct ieee80211_tx_info *info;
struct memrecord *range;
@@ -1014,6 +1016,7 @@
}
}
+ entry = priv->tx_queue.next;
while (left--) {
u32 hole_size;
info = IEEE80211_SKB_CB(entry);