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authorOliver Neukum <oneukum@suse.com>2019-09-19 10:23:08 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-10-05 12:27:42 +0200
commita4d63b4102316eb10cc1bf37274d50a4d4f8962c (patch)
tree08db0bdb988ae873735b1ec2950193b8d838c9ae
parent608557096364a7307467e3f5b005630dd2835f3e (diff)
usbnet: sanity checking of packet sizes and device mtu
[ Upstream commit 280ceaed79f18db930c0cc8bb21f6493490bf29c ] After a reset packet sizes and device mtu can change and need to be reevaluated to calculate queue sizes. Malicious devices can set this to zero and we divide by it. Introduce sanity checking. Reported-and-tested-by: syzbot+6102c120be558c885f04@syzkaller.appspotmail.com Signed-off-by: Oliver Neukum <oneukum@suse.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/net/usb/usbnet.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 6c531abe198b..5a09aff4155a 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -352,6 +352,8 @@ void usbnet_update_max_qlen(struct usbnet *dev)
{
enum usb_device_speed speed = dev->udev->speed;
+ if (!dev->rx_urb_size || !dev->hard_mtu)
+ goto insanity;
switch (speed) {
case USB_SPEED_HIGH:
dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
@@ -367,6 +369,7 @@ void usbnet_update_max_qlen(struct usbnet *dev)
dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
break;
default:
+insanity:
dev->rx_qlen = dev->tx_qlen = 4;
}
}