From 70c37bf97f2a91accba76080db69144f3b69f736 Mon Sep 17 00:00:00 2001 From: Bjørn Mork Date: Mon, 28 Jan 2013 23:51:28 +0000 Subject: net: usbnet: prevent buggy devices from killing us MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Acked-by: Oliver Neukum Signed-off-by: David S. Miller --- drivers/net/usb/usbnet.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'drivers/net/usb/usbnet.c') diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index f34b2ebee815..977837725726 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) { -- cgit v1.2.3 From bf414b369f158bb527f9f29174ada815f961b44c Mon Sep 17 00:00:00 2001 From: Bjørn Mork Date: Thu, 31 Jan 2013 08:36:05 +0000 Subject: net: usbnet: fix tx_dropped statistics MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It is normal for minidrivers accumulating frames to return NULL from their tx_fixup function. We do not want to count this as a drop, or log any debug messages. A different exit path is therefore chosen for such drivers, skipping the debug message and the tx_dropped increment. The test for accumulating drivers was however completely bogus, making the exit path selection depend on whether the user had enabled tx_err logging or not. This would arbitrarily mess up accounting for both accumulating and non-accumulating minidrivers, and would result in unwanted debug messages for the accumulating drivers. Fix by testing for FLAG_MULTI_PACKET instead, which probably was the intention from the beginning. This usage match the documented behaviour of this flag: Indicates to usbnet, that USB driver accumulates multiple IP packets. Affects statistic (counters) and short packet handling. Signed-off-by: Bjørn Mork Signed-off-by: David S. Miller --- drivers/net/usb/usbnet.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) (limited to 'drivers/net/usb/usbnet.c') diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index 977837725726..5e33606c1366 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -1125,13 +1125,11 @@ netdev_tx_t usbnet_start_xmit (struct sk_buff *skb, if (info->tx_fixup) { skb = info->tx_fixup (dev, skb, GFP_ATOMIC); if (!skb) { - if (netif_msg_tx_err(dev)) { - netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n"); - goto drop; - } else { - /* cdc_ncm collected packet; waits for more */ + /* packet collected; minidriver waiting for more */ + if (info->flags & FLAG_MULTI_PACKET) goto not_drop; - } + netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n"); + goto drop; } } length = skb->len; -- cgit v1.2.3