Patchwork [090/118] usbfs: Always allow ctrl requests with USB_RECIP_ENDPOINT on the ctrl ep

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Submitter Luis Henriques
Date May 7, 2013, 1:38 p.m.
Message ID <>
Download mbox | patch
Permalink /patch/242272/
State New
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Luis Henriques - May 7, 2013, 1:38 p.m. -stable review patch.  If anyone has any objections, please let me know.


From: Hans de Goede <>

commit 1361bf4b9f9ef45e628a5b89e0fd9bedfdcb7104 upstream.

When usbfs receives a ctrl-request from userspace it calls check_ctrlrecip,
which for a request with USB_RECIP_ENDPOINT tries to map this to an interface
to see if this interface is claimed, except for ctrl-requests with a type of

When trying to use this device:
redirected to a Windows vm running on qemu on top of Linux.

The windows driver makes a ctrl-req with USB_TYPE_CLASS and
USB_RECIP_ENDPOINT with index 0, and the mapping of the endpoint (0) to
the interface fails since ep 0 is the ctrl endpoint and thus never is
part of an interface.

This patch fixes this ctrl-req failing by skipping the checkintf call for
USB_RECIP_ENDPOINT ctrl-reqs on the ctrl endpoint.

Reported-by: Dave Stikkolorum <>
Tested-by: Dave Stikkolorum <>
Signed-off-by: Hans de Goede <>
Acked-by: Alan Stern <>
Signed-off-by: Greg Kroah-Hartman <>
Signed-off-by: Luis Henriques <>
 drivers/usb/core/devio.c | 2 ++
 1 file changed, 2 insertions(+)


diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 62679bc..f70b887 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -681,6 +681,8 @@  static int check_ctrlrecip(struct dev_state *ps, unsigned int requesttype,
 	index &= 0xff;
 	switch (requesttype & USB_RECIP_MASK) {
+		if ((index & ~USB_DIR_IN) == 0)
+			return 0;
 		ret = findintfep(ps->dev, index);
 		if (ret >= 0)
 			ret = checkintf(ps, ret);