iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

net: lan78xx: fix division by zero in send path

Browse Source 
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>
This commit is contained in:
Johan Hovold 2021-10-26 12:36:17 +02:00 committed by David S. Miller
parent 6f68cd6348
commit db6c3c064f
1 changed files with 6 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/net/usb/lan78xx.c
View File

@ -4122,6 +4122,12 @@ static int lan78xx_probe(struct usb_interface *intf,
dev->maxpacket = usb_maxpacket(dev->udev, dev->pipe_out, 1); 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. */ /* driver requires remote-wakeup capability during autosuspend. */
intf->needs_remote_wakeup = 1; intf->needs_remote_wakeup = 1;