[PATCH v2] usb: core: clear both ep_in and ep_out for non-ep0 control endpoints

[Hui Peng]

In usb_enable_endpoint(), non-zero control endpoints (where
usb_endpoint_xfer_control(&ep->desc) is true) populate both
dev->ep_in[epnum] and dev->ep_out[epnum] with the same
struct usb_host_endpoint pointer.

However, usb_disable_endpoint() only clears either dev->ep_out[epnum]
or dev->ep_in[epnum] depending on the direction bit of epaddr when
reset_hardware is set, leaving the opposite direction's array slot
pointing to the disabled/freed endpoint.

Clear both dev->ep_out[epnum] and dev->ep_in[epnum] when disabling a
non-ep0 control endpoint with reset_hardware set, and update the
function kerneldoc accordingly.

Tested in QEMU against Linux 7.3.0-rc3 using dummy_hcd and raw-gadget to
enumerate a USB device with a non-zero control endpoint (bEndpointAddress
0x01, bmAttributes USB_ENDPOINT_XFER_CONTROL), verifying that both
dev->ep_in[1] and dev->ep_out[1] are cleared when the interface is
disabled.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@xxxxxxxxxxxxxxx
Assisted-by: LLM
Signed-off-by: Hui Peng <benquike@xxxxxxxxx>
---
Changes in v2:
- Dropped all changes in the other files (config.c, hub.c, port.c,
  devio.c, sysfs.c, and ledtrig-usbport.c) per Alan Stern and Greg
  Kroah-Hartman, keeping only the usb_disable_endpoint() fix in
  drivers/usb/core/message.c.
- Updated the usb_disable_endpoint() kerneldoc comment and commit
  description per Alan Stern.

 drivers/usb/core/message.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 75e2bfd744a9..0cd6dd2b6334 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1337,7 +1337,8 @@ static void remove_intf_ep_devs(struct usb_interface *intf)
  *
  * Disables the endpoint for URB submission and nukes all pending URBs.
  * If @reset_hardware is set then also deallocates hcd/hardware state
- * for the endpoint.
+ * for the endpoint (clearing both ep_in and ep_out pointers for
+ * bidirectional non-ep0 control endpoints).
  */
 void usb_disable_endpoint(struct usb_device *dev, unsigned int epaddr,
 		bool reset_hardware)
@@ -1358,6 +1359,11 @@ void usb_disable_endpoint(struct usb_device *dev, unsigned int epaddr,
 			dev->ep_in[epnum] = NULL;
 	}
 	if (ep) {
+		if (reset_hardware && epnum != 0 &&
+		    usb_endpoint_xfer_control(&ep->desc)) {
+			dev->ep_out[epnum] = NULL;
+			dev->ep_in[epnum] = NULL;
+		}
 		ep->enabled = 0;
 		usb_hcd_flush_endpoint(dev, ep);
 		if (reset_hardware)
-- 
2.47.3