From 7d602f30149a117eea260208b1661bc404c21dfd Mon Sep 17 00:00:00 2001 From: Frank Li Date: Wed, 8 Jun 2022 14:04:30 -0500 Subject: [PATCH] usb: cdns3 fix use-after-free at workaround 2 BUG: KFENCE: use-after-free read in __list_del_entry_valid+0x10/0xac cdns3_wa2_remove_old_request() { ... kfree(priv_req->request.buf); cdns3_gadget_ep_free_request(&priv_ep->endpoint, &priv_req->request); list_del_init(&priv_req->list); ^^^ use after free ... } cdns3_gadget_ep_free_request() free the space pointed by priv_req, but priv_req is used in the following list_del_init(). This patch move list_del_init() before cdns3_gadget_ep_free_request(). Signed-off-by: Frank Li Signed-off-by: Faqiang Zhu Link: https://lore.kernel.org/r/20220608190430.2814358-1-Frank.Li@nxp.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/cdns3/cdns3-gadget.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c index 5c15c48952a6..29662c8ac024 100644 --- a/drivers/usb/cdns3/cdns3-gadget.c +++ b/drivers/usb/cdns3/cdns3-gadget.c @@ -625,9 +625,9 @@ static void cdns3_wa2_remove_old_request(struct cdns3_endpoint *priv_ep) trace_cdns3_wa2(priv_ep, "removes eldest request"); kfree(priv_req->request.buf); + list_del_init(&priv_req->list); cdns3_gadget_ep_free_request(&priv_ep->endpoint, &priv_req->request); - list_del_init(&priv_req->list); --priv_ep->wa2_counter; if (!chain)