path: root/net
diff options
authorTom Herbert <therbert@google.com>2010-07-14 20:50:29 -0700
committerDavid S. Miller <davem@davemloft.net>2010-07-14 20:50:29 -0700
commitb0f77d0eae0c58a5a9691a067ada112ceeae2d00 (patch)
tree2bab159a95f51e32dbb4eb2d554328de3190c678 /net
parent91a72a70594e5212c97705ca6a694bd307f7a26b (diff)
net: fix problem in reading sock TX queue
Fix problem in reading the tx_queue recorded in a socket. In dev_pick_tx, the TX queue is read by doing a check with sk_tx_queue_recorded on the socket, followed by a sk_tx_queue_get. The problem is that there is not mutual exclusion across these calls in the socket so it it is possible that the queue in the sock can be invalidated after sk_tx_queue_recorded is called so that sk_tx_queue get returns -1, which sets 65535 in queue_index and thus dev_pick_tx returns 65536 which is a bogus queue and can cause crash in dev_queue_xmit. We fix this by only calling sk_tx_queue_get which does the proper checks. The interface is that sk_tx_queue_get returns the TX queue if the sock argument is non-NULL and TX queue is recorded, else it returns -1. sk_tx_queue_recorded is no longer used so it can be completely removed. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
1 files changed, 3 insertions, 4 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 4b05fdf762a..0ea10f849be 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2029,12 +2029,11 @@ static inline u16 dev_cap_txqueue(struct net_device *dev, u16 queue_index)
static struct netdev_queue *dev_pick_tx(struct net_device *dev,
struct sk_buff *skb)
- u16 queue_index;
+ int queue_index;
struct sock *sk = skb->sk;
- if (sk_tx_queue_recorded(sk)) {
- queue_index = sk_tx_queue_get(sk);
- } else {
+ queue_index = sk_tx_queue_get(sk);
+ if (queue_index < 0) {
const struct net_device_ops *ops = dev->netdev_ops;
if (ops->ndo_select_queue) {