linux-kernel - [PATCH 4.18 33/44] usb: cdc_acm: Do not leak URB buffers

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:   Thu, 11 Oct 2018 17:40:11 +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, Romain Izard <romain.izard.pro@...il.com>,
        Oliver Neukum <oneukum@...e.com>
Subject: [PATCH 4.18 33/44] usb: cdc_acm: Do not leak URB buffers

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

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

From: Romain Izard <romain.izard.pro@...il.com>

commit f2924d4b16ae138c2de6a0e73f526fb638330858 upstream.

When the ACM TTY port is disconnected, the URBs it uses must be killed, and
then the buffers must be freed. Unfortunately a previous refactor removed
the code freeing the buffers because it looked extremely similar to the
code killing the URBs.

As a result, there were many new leaks for each plug/unplug cycle of a
CDC-ACM device, that were detected by kmemleak.

Restore the missing code, and the memory leak is removed.

Fixes: ba8c931ded8d ("cdc-acm: refactor killing urbs")
Signed-off-by: Romain Izard <romain.izard.pro@...il.com>
Acked-by: Oliver Neukum <oneukum@...e.com>
Cc: stable <stable@...r.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/usb/class/cdc-acm.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -1514,6 +1514,7 @@ static void acm_disconnect(struct usb_in
 {
 	struct acm *acm = usb_get_intfdata(intf);
 	struct tty_struct *tty;
+	int i;
 
 	/* sibling interface is already cleaning up */
 	if (!acm)
@@ -1544,6 +1545,11 @@ static void acm_disconnect(struct usb_in
 
 	tty_unregister_device(acm_tty_driver, acm->minor);
 
+	usb_free_urb(acm->ctrlurb);
+	for (i = 0; i < ACM_NW; i++)
+		usb_free_urb(acm->wb[i].urb);
+	for (i = 0; i < acm->rx_buflimit; i++)
+		usb_free_urb(acm->read_urbs[i]);
 	acm_write_buffers_free(acm);
 	usb_free_coherent(acm->dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
 	acm_read_buffers_free(acm);