patch "usb: renesas_usbhs: fix to avoid using a disabled ep in" added to usb-linus

This is a note to let you know that I've just added the patch titled

usb: renesas_usbhs: fix to avoid using a disabled ep in

to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From: Yoshihiro Shimoda <[email protected]>
Date: Mon, 4 Apr 2016 20:40:20 +0900
Subject: usb: renesas_usbhs: fix to avoid using a disabled ep in
usbhsg_queue_done()

This patch fixes an issue that usbhsg_queue_done() may cause kernel panic when dma callback is running and usb_ep_disable() is called by interrupt handler. (Especially, we can reproduce this issue using g_audio with usb-dmac driver.)

For example of a flow:
usbhsf_dma_complete (on tasklet)
--> usbhsf_pkt_handler (on tasklet)
--> usbhsg_queue_done (on tasklet)
*** interrupt happened and usb_ep_disable() is called *** --> usbhsg_queue_pop (on tasklet)
Then, oops happened.

---
 drivers/usb/renesas_usbhs/mod_gadget.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

index 664b263e4b20..53d104b56ef1 100644
@@ -158,10 +158,14 @@ static void usbhsg_queue_done(struct usbhs_priv *priv, struct usbhs_pkt *pkt)
 	struct usbhs_pipe *pipe = pkt->pipe;
 	struct usbhsg_uep *uep = usbhsg_pipe_to_uep(pipe);
 	struct usbhsg_request *ureq = usbhsg_pkt_to_ureq(pkt);
+	unsigned long flags;
 
 	ureq->req.actual = pkt->actual;
 
-	usbhsg_queue_pop(uep, ureq, 0);
+	usbhs_lock(priv, flags);
+	if (uep)
+		__usbhsg_queue_pop(uep, ureq, 0);
+	usbhs_unlock(priv, flags);
 }
 
 static void usbhsg_queue_push(struct usbhsg_uep *uep,

2.8.0