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Message-ID: <20230914015656.20856-1-xingxing.luo@unisoc.com>
Date: Thu, 14 Sep 2023 09:56:56 +0800
From: Xingxing Luo <xingxing.luo@...soc.com>
To: <b-liu@...com>, <gregkh@...uxfoundation.org>
CC: <linux-usb@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<xingxing0070.luo@...il.com>, <Zhiyong.Liu@...soc.com>,
<Cixi.Geng1@...soc.com>, <Orson.Zhai@...soc.com>,
<zhang.lyra@...il.com>
Subject: [PATCH] usb: musb: Get the musb_qh poniter after musb_giveback
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")
Signed-off-by: Xingxing Luo <xingxing.luo@...soc.com>
---
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 a02c29216955..9df27db5847a 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 somtimes qh
+ * may freed, need 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 != NULL && 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);
--
2.17.1
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