linux-kernel - [21/27] USB: Fix bad dma problem on WDM device disconnect

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]

Message-Id: <20120123234203.473278078@clark.kroah.org>
Date:	Mon, 23 Jan 2012 15:41:07 -0800
From:	Greg KH <gregkh@...e.de>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:	torvalds@...ux-foundation.org, akpm@...ux-foundation.org,
	alan@...rguk.ukuu.org.uk,
	Robert Lukassen <robert.lukassen@...tom.com>,
	Bjørn Mork <bjorn@...k.no>
Subject: [21/27] USB: Fix bad dma problem on WDM device disconnect

2.6.32-longterm review patch.  If anyone has any objections, please let me know.

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

From: Robert Lukassen <Robert.Lukassen@...tom.com>

commit 878b753e32ca765cd346a5d3038d630178ec78ff upstream.
[ changed s/usb_free_coherent/usb_buffer_free/ for 2.6.32.x]

In the WDM class driver a disconnect event leads to calls to
usb_free_coherent to put back two USB DMA buffers allocated earlier.
The call to usb_free_coherent uses a different size parameter
(desc->wMaxCommand) than the corresponding call to usb_alloc_coherent
(desc->bMaxPacketSize0).

When a disconnect event occurs, this leads to 'bad dma' complaints
from usb core because the USB DMA buffer is being pushed back to the
'buffer-2048' pool from which it has not been allocated.

This patch against the most recent linux-2.6 kernel ensures that the
parameters used by usb_alloc_coherent & usb_free_coherent calls in
cdc-wdm.c match.

Signed-off-by: Robert Lukassen <robert.lukassen@...tom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>
Signed-off-by: Bjørn Mork <bjorn@...k.no>

---
 drivers/usb/class/cdc-wdm.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -277,7 +277,7 @@ static void cleanup(struct wdm_device *d
 			desc->sbuf,
 			desc->validity->transfer_dma);
 	usb_buffer_free(interface_to_usbdev(desc->intf),
-			desc->wMaxCommand,
+			desc->bMaxPacketSize0,
 			desc->inbuf,
 			desc->response->transfer_dma);
 	kfree(desc->orq);

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/