usb: cdns3 fix use-after-free at workaround 2
authorFrank Li <Frank.Li@nxp.com>
Wed, 8 Jun 2022 19:04:30 +0000 (14:04 -0500)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 25 Aug 2022 09:40:31 +0000 (11:40 +0200)
[ Upstream commit 7d602f30149a117eea260208b1661bc404c21dfd ]

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 <Frank.Li@nxp.com>
Signed-off-by: Faqiang Zhu <faqiang.zhu@nxp.com>
Link: https://lore.kernel.org/r/20220608190430.2814358-1-Frank.Li@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/usb/cdns3/cdns3-gadget.c

index ae049eb28b93c39ede16857b39d8f9d4ba9d74d0..4bcaed787c0f30ad2f5e5f7caed17c4d8228e4ad 100644 (file)
@@ -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)