From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20120620173041.312743596@linuxfoundation.org> Date: Wed, 20 Jun 2012 10:30:59 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Daniel Mack , bEN , Ivan Perrone Subject: [ 20/20] USB: fix gathering of interface associations In-Reply-To: <20120620173044.GA6910@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Mack commit b3a3dd074f7053ef824ad077e5331b52220ceba1 upstream. TEAC's UD-H01 (and probably other devices) have a gap in the interface number allocation of their descriptors: Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 220 bNumInterfaces 3 [...] Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 [...] Interface Association: bLength 8 bDescriptorType 11 bFirstInterface 2 bInterfaceCount 2 bFunctionClass 1 Audio bFunctionSubClass 0 bFunctionProtocol 32 iFunction 4 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 2 bAlternateSetting 0 [...] Once a configuration is selected, usb_set_configuration() walks the known interfaces of a given configuration and calls find_iad() on each of them to set the interface association pointer the interface is included in. The problem here is that the loop variable is taken for the interface number in the comparison logic that gathers the association. Which is fine as long as the descriptors are sane. In the case above, however, the logic gets out of sync and the interface association fields of all interfaces beyond the interface number gap are wrong. Fix this by passing the interface's bInterfaceNumber to find_iad() instead. Signed-off-by: Daniel Mack Reported-by: bEN Reported-by: Ivan Perrone Tested-by: ivan perrone Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/message.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1803,7 +1803,6 @@ free_interfaces: intfc = cp->intf_cache[i]; intf->altsetting = intfc->altsetting; intf->num_altsetting = intfc->num_altsetting; - intf->intf_assoc = find_iad(dev, cp, i); kref_get(&intfc->ref); alt = usb_altnum_to_altsetting(intf, 0); @@ -1816,6 +1815,8 @@ free_interfaces: if (!alt) alt = &intf->altsetting[0]; + intf->intf_assoc = + find_iad(dev, cp, alt->desc.bInterfaceNumber); intf->cur_altsetting = alt; usb_enable_interface(dev, intf, true); intf->dev.parent = &dev->dev;