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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Oliver Neukum <oneukum@suse.com>,
	"David S . Miller" <davem@davemloft.net>,
	Sasha Levin <sashal@kernel.org>,
	netdev@vger.kernel.org, linux-usb@vger.kernel.org
Subject: [PATCH AUTOSEL 4.4 14/15] usbnet: sanity checking of packet sizes and device mtu
Date: Tue,  1 Oct 2019 12:45:32 -0400	[thread overview]
Message-ID: <20191001164533.16915-14-sashal@kernel.org> (raw)
In-Reply-To: <20191001164533.16915-1-sashal@kernel.org>

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 6c531abe198bb..5a09aff4155ab 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;
 	}
 }
-- 
2.20.1


  parent reply	other threads:[~2019-10-01 16:46 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20191001164533.16915-1-sashal@kernel.org>
2019-10-01 16:45 ` [PATCH AUTOSEL 4.4 07/15] cdc_ncm: fix divide-by-zero caused by invalid wMaxPacketSize Sasha Levin
2019-10-01 16:45 ` [PATCH AUTOSEL 4.4 08/15] usbnet: ignore endpoints with " Sasha Levin
2019-10-01 16:45 ` [PATCH AUTOSEL 4.4 09/15] net/phy: fix DP83865 10 Mbps HDX loopback disable function Sasha Levin
2019-10-01 16:45 ` [PATCH AUTOSEL 4.4 12/15] arcnet: provide a buffer big enough to actually receive packets Sasha Levin
2019-10-01 16:45 ` Sasha Levin [this message]
2019-10-01 16:45 ` [PATCH AUTOSEL 4.4 15/15] sch_netem: fix a divide by zero in tabledist() Sasha Levin

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