From 38f3ad5e7463d4dd490a8081a5f3f9f2dec7ecd6 Mon Sep 17 00:00:00 2001 From: Felipe Balbi Date: Thu, 12 Jun 2008 10:49:47 +0300 Subject: [PATCH] usb: hub: add check for unsupported bus topology We can't allow hubs on the 7th tier as they would allow devices on the 8th tier. Signed-off-by: Felipe Balbi Cc: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/devices.c | 2 -- drivers/usb/core/hcd.h | 2 ++ drivers/usb/core/hub.c | 6 ++++++ 3 files changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/usb/core/devices.c b/drivers/usb/core/devices.c index a681d9b92bda..6ec38175a817 100644 --- a/drivers/usb/core/devices.c +++ b/drivers/usb/core/devices.c @@ -61,8 +61,6 @@ #include "usb.h" #include "hcd.h" -#define MAX_TOPO_LEVEL 6 - /* Define ALLOW_SERIAL_NUMBER if you want to see the serial number of devices */ #define ALLOW_SERIAL_NUMBER diff --git a/drivers/usb/core/hcd.h b/drivers/usb/core/hcd.h index 50b8bb2d1212..5b0b59b0d89b 100644 --- a/drivers/usb/core/hcd.h +++ b/drivers/usb/core/hcd.h @@ -21,6 +21,8 @@ #include +#define MAX_TOPO_LEVEL 6 + /* This file contains declarations of usbcore internals that are mostly * used or exposed by Host Controller Drivers. */ diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index e678ed8bd8c2..3251120b414e 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -1051,6 +1051,12 @@ static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id) desc = intf->cur_altsetting; hdev = interface_to_usbdev(intf); + if (hdev->level == MAX_TOPO_LEVEL) { + dev_err(&intf->dev, "Unsupported bus topology: " + "hub nested too deep\n"); + return -E2BIG; + } + #ifdef CONFIG_USB_OTG_BLACKLIST_HUB if (hdev->parent) { dev_warn(&intf->dev, "ignoring external hub\n"); -- 2.20.1