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authorJohan Hovold <johan@kernel.org>2021-10-26 13:36:17 +0300
committerDavid S. Miller <davem@davemloft.net>2021-10-26 17:18:39 +0300
commitdb6c3c064f5d55fa9969f33eafca3cdbefbb3541 (patch)
tree72f85bb6cd12f2d8190537f1e3ede3816b7c50d4
parent6f68cd634856f8ca93bafd623ba5357e0f648c68 (diff)
downloadlinux-db6c3c064f5d55fa9969f33eafca3cdbefbb3541.tar.xz
net: lan78xx: fix division by zero in send path
Add the missing endpoint max-packet sanity check to probe() to avoid division by zero in lan78xx_tx_bh() in case a malicious device has broken descriptors (or when doing descriptor fuzz testing). Note that USB core will reject URBs submitted for endpoints with zero wMaxPacketSize but that drivers doing packet-size calculations still need to handle this (cf. commit 2548288b4fb0 ("USB: Fix: Don't skip endpoint descriptors with maxpacket=0")). Fixes: 55d7de9de6c3 ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver") Cc: stable@vger.kernel.org # 4.3 Cc: Woojung.Huh@microchip.com <Woojung.Huh@microchip.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/usb/lan78xx.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index 793f8fbe0069..63cd72c5f580 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -4122,6 +4122,12 @@ static int lan78xx_probe(struct usb_interface *intf,
dev->maxpacket = usb_maxpacket(dev->udev, dev->pipe_out, 1);
+ /* Reject broken descriptors. */
+ if (dev->maxpacket == 0) {
+ ret = -ENODEV;
+ goto out4;
+ }
+
/* driver requires remote-wakeup capability during autosuspend. */
intf->needs_remote_wakeup = 1;