From b1e24de475bf2d66fffc9103f3444b783527d55a Mon Sep 17 00:00:00 2001 From: Shuangpeng Bai Date: Wed, 5 Aug 2026 21:35:02 -0400 Subject: [PATCH] USB: c67x00: fix use-after-free in c67x00_add_iso_urb() When TD creation fails for the last packet of an isochronous URB, c67x00_add_iso_urb() gives the URB back before updating the endpoint scheduling state. c67x00_giveback_urb() frees the URB private data, and the completion callback may release the final URB reference. The following accesses to urbp->ep_data, urb->interval, and urbp->cnt can therefore use freed memory. Update next_frame and cnt before giving back the failed final packet, making the giveback the last operation that uses the URB and its private data. Fixes: e9b29ffc519b ("USB: add Cypress c67x00 OTG controller HCD driver") Cc: stable@vger.kernel.org Signed-off-by: Shuangpeng Bai Link: https://patch.msgid.link/20260806013502.322067-1-shuangpeng.kernel@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/c67x00/c67x00-sched.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/usb/c67x00/c67x00-sched.c b/drivers/usb/c67x00/c67x00-sched.c index a832f5696f2a..ae6c94f41cb3 100644 --- a/drivers/usb/c67x00/c67x00-sched.c +++ b/drivers/usb/c67x00/c67x00-sched.c @@ -761,13 +761,13 @@ static int c67x00_add_iso_urb(struct c67x00_hcd *c67x00, struct urb *urb) ret); urb->iso_frame_desc[urbp->cnt].actual_length = 0; urb->iso_frame_desc[urbp->cnt].status = ret; - if (urbp->cnt + 1 == urb->number_of_packets) - c67x00_giveback_urb(c67x00, urb, 0); } urbp->ep_data->next_frame = frame_add(urbp->ep_data->next_frame, urb->interval); urbp->cnt++; + if (ret && urbp->cnt == urb->number_of_packets) + c67x00_giveback_urb(c67x00, urb, 0); } return 0; }