linux-kernel - [PATCH 4.16 017/196] usb: musb: gadget: misplaced out of bounds check

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:   Sun, 22 Apr 2018 15:50:37 +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, Heinrich Schuchardt <xypron.glpk@....de>,
        Bin Liu <b-liu@...com>
Subject: [PATCH 4.16 017/196] usb: musb: gadget: misplaced out of bounds check

4.16-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Heinrich Schuchardt <xypron.glpk@....de>

commit af6f8529098aeb0e56a68671b450cf74e7a64fcd upstream.

musb->endpoints[] has array size MUSB_C_NUM_EPS.
We must check array bounds before accessing the array and not afterwards.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@....de>
Signed-off-by: Bin Liu <b-liu@...com>
Cc: stable <stable@...r.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/usb/musb/musb_gadget_ep0.c |   14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

--- a/drivers/usb/musb/musb_gadget_ep0.c
+++ b/drivers/usb/musb/musb_gadget_ep0.c
@@ -89,15 +89,19 @@ static int service_tx_status_request(
 		}
 
 		is_in = epnum & USB_DIR_IN;
-		if (is_in) {
-			epnum &= 0x0f;
+		epnum &= 0x0f;
+		if (epnum >= MUSB_C_NUM_EPS) {
+			handled = -EINVAL;
+			break;
+		}
+
+		if (is_in)
 			ep = &musb->endpoints[epnum].ep_in;
-		} else {
+		else
 			ep = &musb->endpoints[epnum].ep_out;
-		}
 		regs = musb->endpoints[epnum].regs;
 
-		if (epnum >= MUSB_C_NUM_EPS || !ep->desc) {
+		if (!ep->desc) {
 			handled = -EINVAL;
 			break;
 		}