4.5-stable review patch. If anyone has any objections, please let me know.
------------------ From: Yoshihiro Shimoda <[email protected]> commit 4fccb0767fdbdb781a9c5b5c15ee7b219443c89d upstream. 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. Fixes: e73a989 ("usb: renesas_usbhs: add DMAEngine support") Signed-off-by: Yoshihiro Shimoda <[email protected]> Signed-off-by: Felipe Balbi <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/usb/renesas_usbhs/mod_gadget.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/usb/renesas_usbhs/mod_gadget.c +++ b/drivers/usb/renesas_usbhs/mod_gadget.c @@ -158,10 +158,14 @@ static void usbhsg_queue_done(struct usb 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,
