USB: CVE-2018-19985

USB: hso: Fix OOB memory access in hso_probe/hso_get_config_data

References:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=linux-4.14.y&id=49be8dc589aee04c64d61e362c5029ab20fd6fd7

Change-Id: I26c1c763c075d8719ac4bff276d8b1785ae46ad8
Signed-off-by: Andreas Wellving <andreas.wellving@enea.com>

2 files changed, 76 insertions, 0 deletions

diff --git a/patches/cve/4.14.x.scc b/patches/cve/4.14.x.scc
index db984b6..36143b1 100644
--- a/patches/cve/4.14.x.scc
+++ b/patches/cve/4.14.x.scc
@@ -17,3 +17,5 @@ patch CVE-2018-18397-userfaultfd-use-ENOENT-instead-of-EFAULT-if-the-atom.patch
 patch CVE-2018-14625-vhost-vsock-fix-use-after-free-in-network-stack-call.patch
 patch CVE-2018-19824-ALSA-usb-audio-Fix-UAF-decrement-if-card-has-no-live.patch
 patch CVE-2018-20169-USB-check-usb_get_extra_descriptor-for-proper-size.patch
+CVEs fixed in 4.14.91:
+patch CVE-2018-19985-USB-hso-Fix-OOB-memory-access-in-hso_probe-hso_get_c.patch
diff --git a/patches/cve/CVE-2018-19985-USB-hso-Fix-OOB-memory-access-in-hso_probe-hso_get_c.patch b/patches/cve/CVE-2018-19985-USB-hso-Fix-OOB-memory-access-in-hso_probe-hso_get_c.patch
new file mode 100644
index 0000000..9d81696
--- /dev/null
+++ b/patches/cve/CVE-2018-19985-USB-hso-Fix-OOB-memory-access-in-hso_probe-hso_get_c.patch
@@ -0,0 +1,74 @@
+From 49be8dc589aee04c64d61e362c5029ab20fd6fd7 Mon Sep 17 00:00:00 2001
+From: Hui Peng <benquike@gmail.com>
+Date: Wed, 12 Dec 2018 12:42:24 +0100
+Subject: [PATCH] USB: hso: Fix OOB memory access in
+ hso_probe/hso_get_config_data
+
+commit 5146f95df782b0ac61abde36567e718692725c89 upstream.
+
+The function hso_probe reads if_num from the USB device (as an u8) and uses
+it without a length check to index an array, resulting in an OOB memory read
+in hso_probe or hso_get_config_data.
+
+Add a length check for both locations and updated hso_probe to bail on
+error.
+
+This issue has been assigned CVE-2018-19985.
+
+CVE: CVE-2018-19985
+Upstream-Status: Backport
+
+Reported-by: Hui Peng <benquike@gmail.com>
+Reported-by: Mathias Payer <mathias.payer@nebelwelt.net>
+Signed-off-by: Hui Peng <benquike@gmail.com>
+Signed-off-by: Mathias Payer <mathias.payer@nebelwelt.net>
+Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Signed-off-by: Andreas Wellving <andreas.wellving@enea.com>
+---
+ drivers/net/usb/hso.c | 18 ++++++++++++++++--
+ 1 file changed, 16 insertions(+), 2 deletions(-)
+
+diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
+index d7a3379ea668..18a0952f68a8 100644
+--- a/drivers/net/usb/hso.c
++++ b/drivers/net/usb/hso.c
+@@ -2806,6 +2806,12 @@ static int hso_get_config_data(struct usb_interface *interface)
+                return -EIO;
+        }
+ 
++       /* check if we have a valid interface */
++       if (if_num > 16) {
++               kfree(config_data);
++               return -EINVAL;
++       }
++
+        switch (config_data[if_num]) {
+        case 0x0:
+                result = 0;
+@@ -2876,10 +2882,18 @@ static int hso_probe(struct usb_interface *interface,
+ 
+        /* Get the interface/port specification from either driver_info or from
+         * the device itself */
+-       if (id->driver_info)
++       if (id->driver_info) {
++               /* if_num is controlled by the device, driver_info is a 0 terminated
++                * array. Make sure, the access is in bounds! */
++               for (i = 0; i <= if_num; ++i)
++                       if (((u32 *)(id->driver_info))[i] == 0)
++                               goto exit;
+                port_spec = ((u32 *)(id->driver_info))[if_num];
+-       else
++       } else {
+                port_spec = hso_get_config_data(interface);
++               if (port_spec < 0)
++                       goto exit;
++       }
+ 
+        /* Check if we need to switch to alt interfaces prior to port
+         * configuration */
+-- 
+2.19.2
+