linux-kernel - [PATCH 5.4 350/389] usb: cdns3 fix use-after-free at workaround 2

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20220823080130.162788721@linuxfoundation.org>
Date:   Tue, 23 Aug 2022 10:27:08 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Frank Li <Frank.Li@....com>,
        Faqiang Zhu <faqiang.zhu@....com>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.4 350/389] usb: cdns3 fix use-after-free at workaround 2

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

[ 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@....com>
Signed-off-by: Faqiang Zhu <faqiang.zhu@....com>
Link: https://lore.kernel.org/r/20220608190430.2814358-1-Frank.Li@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/usb/cdns3/gadget.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
index 296f2ee1b680..a9399f2b3930 100644
--- a/drivers/usb/cdns3/gadget.c
+++ b/drivers/usb/cdns3/gadget.c
@@ -549,9 +549,9 @@ 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)
-- 
2.35.1