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authorBjørn Mork <bjorn@mork.no>2013-01-28 23:51:28 +0000
committerDavid S. Miller <davem@davemloft.net>2013-01-30 17:35:44 -0500
commit70c37bf97f2a91accba76080db69144f3b69f736 (patch)
tree2c5b72a06bba90a0cfbf4b1ae93c4ba5d41278ef /drivers/net/usb
parent6cdd20c380eb62eab757c5a6ccc90dac7ecd774b (diff)
net: usbnet: prevent buggy devices from killing us
A device sending 0 length frames as fast as it can has been observed killing the host system due to the resulting memory pressure. Temporarily disable RX skb allocation and URB submission when the current error ratio is high, preventing us from trying to allocate an infinite number of skbs. Reenable as soon as we are finished processing the done queue, allowing the device to continue working after short error bursts. Signed-off-by: Bjørn Mork <bjorn@mork.no> Acked-by: Oliver Neukum <oneukum@suse.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/usb')
-rw-r--r--drivers/net/usb/usbnet.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index f34b2ebee81..97783772572 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -380,6 +380,12 @@ static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
unsigned long lockflags;
size_t size = dev->rx_urb_size;
+ /* prevent rx skb allocation when error ratio is high */
+ if (test_bit(EVENT_RX_KILL, &dev->flags)) {
+ usb_free_urb(urb);
+ return -ENOLINK;
+ }
+
skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
if (!skb) {
netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
@@ -539,6 +545,17 @@ block:
break;
}
+ /* stop rx if packet error rate is high */
+ if (++dev->pkt_cnt > 30) {
+ dev->pkt_cnt = 0;
+ dev->pkt_err = 0;
+ } else {
+ if (state == rx_cleanup)
+ dev->pkt_err++;
+ if (dev->pkt_err > 20)
+ set_bit(EVENT_RX_KILL, &dev->flags);
+ }
+
state = defer_bh(dev, skb, &dev->rxq, state);
if (urb) {
@@ -791,6 +808,11 @@ int usbnet_open (struct net_device *net)
(dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
"simple");
+ /* reset rx error state */
+ dev->pkt_cnt = 0;
+ dev->pkt_err = 0;
+ clear_bit(EVENT_RX_KILL, &dev->flags);
+
// delay posting reads until we're fully open
tasklet_schedule (&dev->bh);
if (info->manage_power) {
@@ -1254,6 +1276,9 @@ static void usbnet_bh (unsigned long param)
}
}
+ /* restart RX again after disabling due to high error rate */
+ clear_bit(EVENT_RX_KILL, &dev->flags);
+
// waiting for all pending urbs to complete?
if (dev->wait) {
if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {