[PATCH 6.6 187/299] usb: cdns3: fix memory double free when handle zero packet

Greg Kroah-Hartman
2024-02-27T13:56:46Z

From: Frank Li <Frank.Li@nxp.com>

commit 5fd9e45f1ebcd57181358af28506e8a661a260b3 upstream.

829 if (request->complete) {
830 spin_unlock(&priv_dev->lock);
831 usb_gadget_giveback_request(&priv_ep->endpoint,
832 request);
833 spin_lock(&priv_dev->lock);
834 }
835
836 if (request->buf == priv_dev->zlp_buf)
837 cdns3_gadget_ep_free_request(&priv_ep->endpoint, request);

Driver append an additional zero packet request when queue a packet, which
length mod max packet size is 0. When transfer complete, run to line 831,
usb_gadget_giveback_request() will free this requestion. 836 condition is
true, so cdns3_gadget_ep_free_request() free this request again.

Log:

[ 1920.140696][ T150] BUG: KFENCE: use-after-free read in cdns3_gadget_giveback+0x134/0x2c0 [cdns3]
[ 1920.140696][ T150]
[ 1920.151837][ T150] Use-after-free read at 0x000000003d1cd10b (in kfence-#36):
[ 1920.159082][ T150] cdns3_gadget_giveback+0x134/0x2c0 [cdns3]
[ 1920.164988][ T150] cdns3_transfer_completed+0x438/0x5f8 [cdns3]

Add check at line 829, skip call usb_gadget_giveback_request() if it is
additional zero length packet request. Needn't call
usb_gadget_giveback_request() because it is allocated in this driver.

Cc: stable@vger.kernel.org
Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
Acked-by: Peter Chen <peter.chen@kernel.org>
Link: https://lore.kernel.org/r/20240202154217.661867-2-Frank.Li@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/cdns3/cdns3-gadget.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/usb/cdns3/cdns3-gadget.c
+++ b/drivers/usb/cdns3/cdns3-gadget.c
@@ -828,7 +828,11 @@ void cdns3_gadget_giveback(struct cdns3_
return;
}

- if (request->complete) {
+ /*
+ * zlp request is appended by driver, needn't call usb_gadget_giveback_request() to notify
+ * gadget composite driver.
+ */
+ if (request->complete && request->buf != priv_dev->zlp_buf) {
spin_unlock(&priv_dev->lock);
usb_gadget_giveback_request(&priv_ep->endpoint,
request);