[PATCH AUTOSEL 5.2 61/63] usbnet: sanity checking of packet sizes and device mtu
From: Sasha Levin <sashal@kernel.org>
Date: 2019-10-01 16:54:27
Also in:
linux-usb, lkml, stable
Subsystem:
networking drivers, the rest, usb "usbnet" driver framework, usb networking drivers · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Oliver Neukum
From: Oliver Neukum <oneukum@suse.com> [ 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: Sasha Levin <sashal@kernel.org> --- drivers/net/usb/usbnet.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 07c00e378a5cd..ef1d667b0108b 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c@@ -344,6 +344,8 @@ 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;
@@ -360,6 +362,7 @@ 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; } }
--
2.20.1