Path: csiph.com!news.redatomik.org!weretis.net!feeder4.news.weretis.net!news.unit0.net!news.panservice.it!diesel.cu.mi.it!bofh.it!news.nic.it!robomod From: Willy Tarreau Newsgroups: linux.kernel Subject: [PATCH 3.10 163/250] USB: serial: safe_serial: fix information leak in completion handler Date: Thu, 08 Jun 2017 01:10:02 +0200 Message-ID: References: X-Original-To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a Sender: robomod@news.nic.it List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Approved: robomod@news.nic.it Lines: 35 Organization: linux.* mail to news gateway X-Original-Cc: Johan Hovold , Willy Tarreau X-Original-Date: Thu, 8 Jun 2017 00:59:09 +0200 X-Original-Message-ID: <1496876436-32402-164-git-send-email-w@1wt.eu> X-Original-References: <1496876436-32402-1-git-send-email-w@1wt.eu> X-Original-Sender: linux-kernel-owner@vger.kernel.org Xref: csiph.com linux.kernel:1660313 From: Johan Hovold commit 8c76d7cd520ebffc1ea9ea0850d87a224a50c7f2 upstream. Add missing sanity check to the bulk-in completion handler to avoid an integer underflow that could be triggered by a malicious device. This avoids leaking up to 56 bytes from after the URB transfer buffer to user space. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Johan Hovold Signed-off-by: Willy Tarreau --- drivers/usb/serial/safe_serial.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/usb/serial/safe_serial.c b/drivers/usb/serial/safe_serial.c index 21cd7bf..8e24f8f 100644 --- a/drivers/usb/serial/safe_serial.c +++ b/drivers/usb/serial/safe_serial.c @@ -215,6 +215,11 @@ static void safe_process_read_urb(struct urb *urb) if (!safe) goto out; + if (length < 2) { + dev_err(&port->dev, "malformed packet\n"); + return; + } + fcs = fcs_compute10(data, length, CRC10_INITFCS); if (fcs) { dev_err(&port->dev, "%s - bad CRC %x\n", __func__, fcs); -- 2.8.0.rc2.1.gbe9624a