From fecb419c62c6c4f0223fc7156854f33628762af4 Mon Sep 17 00:00:00 2001 From: Xingxing Luo Date: Tue, 19 Sep 2023 11:30:55 +0800 Subject: [PATCH] usb: musb: Get the musb_qh poniter after musb_giveback commit 33d7e37232155aadebe4145dcc592f00dabd7a2b upstream. When multiple threads are performing USB transmission, musb->lock will be unlocked when musb_giveback is executed. At this time, qh may be released in the dequeue process in other threads, resulting in a wild pointer, so it needs to be here get qh again, and judge whether qh is NULL, and when dequeue, you need to set qh to NULL. Fixes: dbac5d07d13e ("usb: musb: host: don't start next rx urb if current one failed") Cc: stable@vger.kernel.org Signed-off-by: Xingxing Luo Link: https://lore.kernel.org/r/20230919033055.14085-1-xingxing.luo@unisoc.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/musb/musb_host.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c index 9ff7d891b4b76..ef0b1589b10eb 100644 --- a/drivers/usb/musb/musb_host.c +++ b/drivers/usb/musb/musb_host.c @@ -321,10 +321,16 @@ static void musb_advance_schedule(struct musb *musb, struct urb *urb, musb_giveback(musb, urb, status); qh->is_ready = ready; + /* + * musb->lock had been unlocked in musb_giveback, so qh may + * be freed, need to get it again + */ + qh = musb_ep_get_qh(hw_ep, is_in); + /* reclaim resources (and bandwidth) ASAP; deschedule it, and * invalidate qh as soon as list_empty(&hep->urb_list) */ - if (list_empty(&qh->hep->urb_list)) { + if (qh && list_empty(&qh->hep->urb_list)) { struct list_head *head; struct dma_controller *dma = musb->dma_controller; @@ -2398,6 +2404,7 @@ static int musb_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status) * and its URB list has emptied, recycle this qh. */ if (ready && list_empty(&qh->hep->urb_list)) { + musb_ep_set_qh(qh->hw_ep, is_in, NULL); qh->hep->hcpriv = NULL; list_del(&qh->ring); kfree(qh); -- 2.39.5