From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752572AbcFEKwB (ORCPT ); Sun, 5 Jun 2016 06:52:01 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:21742 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752116AbcFEKVt (ORCPT ); Sun, 5 Jun 2016 06:21:49 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ignat Korchagin , Sasha Levin , Paul Gortmaker , Greg Kroah-Hartman , Willy Tarreau Subject: [PATCH 3.10 093/143] USB: usbip: fix potential out-of-bounds write Date: Sun, 5 Jun 2016 12:19:56 +0200 Message-Id: <1465122046-9645-94-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1465122046-9645-1-git-send-email-w@1wt.eu> References: <1465122046-9645-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ignat Korchagin commit b348d7dddb6c4fbfc810b7a0626e8ec9e29f7cbb upstream. Fix potential out-of-bounds write to urb->transfer_buffer usbip handles network communication directly in the kernel. When receiving a packet from its peer, usbip code parses headers according to protocol. As part of this parsing urb->actual_length is filled. Since the input for urb->actual_length comes from the network, it should be treated as untrusted. Any entity controlling the network may put any value in the input and the preallocated urb->transfer_buffer may not be large enough to hold the data. Thus, the malicious entity is able to write arbitrary data to kernel memory. Signed-off-by: Ignat Korchagin Cc: Sasha Levin Signed-off-by: Paul Gortmaker Signed-off-by: Greg Kroah-Hartman Signed-off-by: Willy Tarreau --- drivers/staging/usbip/usbip_common.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/staging/usbip/usbip_common.c b/drivers/staging/usbip/usbip_common.c index 7b97df6..b4f237e 100644 --- a/drivers/staging/usbip/usbip_common.c +++ b/drivers/staging/usbip/usbip_common.c @@ -784,6 +784,17 @@ int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb) if (!(size > 0)) return 0; + if (size > urb->transfer_buffer_length) { + /* should not happen, probably malicious packet */ + if (ud->side == USBIP_STUB) { + usbip_event_add(ud, SDEV_EVENT_ERROR_TCP); + return 0; + } else { + usbip_event_add(ud, VDEV_EVENT_ERROR_TCP); + return -EPIPE; + } + } + ret = usbip_recv(ud->tcp_socket, urb->transfer_buffer, size); if (ret != size) { dev_err(&urb->dev->dev, "recv xbuf, %d\n", ret); -- 2.8.0.rc2.1.gbe9624a