| Message ID | 20211026103617.5686-1-johan@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | db6c3c064f5d55fa9969f33eafca3cdbefbb3541 |
| Headers | show |
| Series | net: lan78xx: fix division by zero in send path | expand |
Hello: This patch was applied to netdev/net.git (master) by David S. Miller <davem@davemloft.net>: On Tue, 26 Oct 2021 12:36:17 +0200 you wrote: > 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")). > > [...] Here is the summary with links: - net: lan78xx: fix division by zero in send path https://git.kernel.org/netdev/net/c/db6c3c064f5d You are awesome, thank you!
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;
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> --- drivers/net/usb/lan78xx.c | 6 ++++++ 1 file changed, 6 insertions(+)