This is a note to let you know that I've just added the patch titled
USB: fix gathering of interface associations
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-fix-gathering-of-interface-associations.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From b3a3dd074f7053ef824ad077e5331b52220ceba1 Mon Sep 17 00:00:00 2001
From: Daniel Mack <[email protected]>
Date: Tue, 12 Jun 2012 20:23:52 +0200
Subject: USB: fix gathering of interface associations
From: Daniel Mack <[email protected]>
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 <[email protected]>
Reported-by: bEN <[email protected]>
Reported-by: Ivan Perrone <[email protected]>
Tested-by: ivan perrone <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
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;
Patches currently in stable-queue which might be from [email protected] are
queue-3.4/usb-fix-gathering-of-interface-associations.patch
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