Commit b8fbaef5 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller

wimax/i2400m: fix erroneous NETDEV_TX_BUSY use

A driver start_xmit() method cannot free skb and return NETDEV_TX_BUSY,
since caller is going to reuse freed skb.

In fact netif_tx_stop_queue() / netif_stop_queue() is needed before
returning NETDEV_TX_BUSY or you can trigger a ksoftirqd fatal loop.

In case of memory allocation error, only safe way is to drop the packet
and return NETDEV_TX_OK

Also increments tx_dropped counter
Signed-off-by: default avatarEric Dumazet <>
Cc: Inaky Perez-Gonzalez <>
Signed-off-by: default avatarDavid S. Miller <>
parent bb6d5e76
......@@ -367,38 +367,28 @@ netdev_tx_t i2400m_hard_start_xmit(struct sk_buff *skb,
struct i2400m *i2400m = net_dev_to_i2400m(net_dev);
struct device *dev = i2400m_dev(i2400m);
int result;
int result = -1;
d_fnstart(3, dev, "(skb %p net_dev %p)\n", skb, net_dev);
if (skb_header_cloned(skb)) {
* Make tcpdump/wireshark happy -- if they are
* running, the skb is cloned and we will overwrite
* the mac fields in i2400m_tx_prep_header. Expand
* seems to fix this...
result = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
if (result) {
result = NETDEV_TX_BUSY;
goto error_expand;
if (skb_header_cloned(skb) &&
pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
goto drop;
if (i2400m->state == I2400M_SS_IDLE)
result = i2400m_net_wake_tx(i2400m, net_dev, skb);
result = i2400m_net_tx(i2400m, net_dev, skb);
if (result < 0)
if (result < 0) {
else {
} else {
net_dev->stats.tx_bytes += skb->len;
result = NETDEV_TX_OK;
d_fnend(3, dev, "(skb %p net_dev %p) = %d\n", skb, net_dev, result);
return result;
return NETDEV_TX_OK;
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