[PATCH 1/2] usb: gadget: composite: fix delayed_status race condition when set_interface
From: Chunfeng Yun <chunfeng.yun@mediatek.com>
Date: 2018-06-22 06:33:34
Also in:
linux-arm-kernel, linux-devicetree, linux-usb, lkml
Subsystem:
the rest, usb subsystem · Maintainers:
Linus Torvalds, Greg Kroah-Hartman
It happens when enable debug log, if set_alt() returns USB_GADGET_DELAYED_STATUS and usb_composite_setup_continue() is called before increasing count of @delayed_status, so fix it by using spinlock of @cdev->lock. Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com> Tested-by: Jay Hsu <redacted> --- drivers/usb/gadget/composite.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index f242c2b..d2fa071 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c@@ -1719,6 +1719,8 @@ static int fill_ext_prop(struct usb_configuration *c, int interface, u8 *buf) */ if (w_value && !f->get_alt) break; + + spin_lock(&cdev->lock); value = f->set_alt(f, w_index, w_value); if (value == USB_GADGET_DELAYED_STATUS) { DBG(cdev,
@@ -1728,6 +1730,7 @@ static int fill_ext_prop(struct usb_configuration *c, int interface, u8 *buf) DBG(cdev, "delayed_status count %d\n", cdev->delayed_status); } + spin_unlock(&cdev->lock); break; case USB_REQ_GET_INTERFACE: if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
--
1.9.1