Commit 769d7368 authored Mar 25, 2013 by David Linares Committed by Greg Kroah-Hartman Mar 25, 2013

USB: hub: Avoid NULL pointer dereference when hub doesn't have any ports



Return an error if hub->descriptor->bNbrPorts==0. Without this additional
check, we can end up doing a "hub->ports = kzalloc(0, GFP_KERNEL)".
This hub->ports pointer will therefore be non-NULL and will be used.
Example of dmesg:
   INIT: usb 1-1: New USB device found, idVendor=0424, idProduct=2512
   usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
   hub 1-1:1.0: USB hub found
   version 2.86 bootinghub 1-1:1.0: 0 ports detected
   Unable to handle kernel NULL pointer dereference at virtual address 00000010

Signed-off-by: David Linares <dlinares.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 5410a473

drivers/usb/core/hub.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -1317,6 +1317,10 @@ static int hub_configure(struct usb_hub *hub,
		message = "hub has too many ports!";
		ret = -ENODEV;
		goto fail;
		} else if (hub->descriptor->bNbrPorts == 0) {
		message = "hub doesn't have any ports!";
		ret = -ENODEV;
		goto fail;
		}

		hdev->maxchild = hub->descriptor->bNbrPorts;

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