USB: CVE-2017-16531

USB: fix out-of-bounds in usb_set_configuration

References:
https://nvd.nist.gov/vuln/detail/CVE-2017-16531
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=bd7a3fe770ebd8391d1c7d072ff88e9e76d063eb
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=linux-4.1.y&id=de5ffcc63dbdaffffd93934003fd527673f4da0a

Change-Id: I04f538f1ee61459772eb21f85764ed76a82fb342
Signed-off-by: Adrian Stratulat <adrian.stratulat@enea.com>

1 files changed, 77 insertions, 0 deletions

diff --git a/patches/cve/CVE-2017-16531.patch b/patches/cve/CVE-2017-16531.patch
new file mode 100644
index 0000000..bc8d2c5
--- /dev/null
+++ b/patches/cve/CVE-2017-16531.patch
@@ -0,0 +1,77 @@
+From de5ffcc63dbdaffffd93934003fd527673f4da0a Mon Sep 17 00:00:00 2001
+From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Date: Tue, 19 Sep 2017 15:07:17 +0200
+Subject: USB: fix out-of-bounds in usb_set_configuration
+
+[ Upstream commit bd7a3fe770ebd8391d1c7d072ff88e9e76d063eb ]
+
+Andrey Konovalov reported a possible out-of-bounds problem for a USB interface
+association descriptor.  He writes:
+        It seems there's no proper size check of a USB_DT_INTERFACE_ASSOCIATION
+        descriptor. It's only checked that the size is >= 2 in
+        usb_parse_configuration(), so find_iad() might do out-of-bounds access
+        to intf_assoc->bInterfaceCount.
+
+And he's right, we don't check for crazy descriptors of this type very well, so
+resolve this problem.  Yet another issue found by syzkaller...
+
+Upstream-Status: Backport [https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=linux-4.1.y&id=de5ffcc63dbdaffffd93934003fd527673f4da0a]
+CVE: CVE-2017-16531
+
+Reported-by: Andrey Konovalov <andreyknvl@google.com>
+Tested-by: Andrey Konovalov <andreyknvl@google.com>
+Cc: stable <stable@vger.kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
+Signed-off-by: Adrian Stratulat <adrian.stratulat@enea.com>
+---
+ drivers/usb/core/config.c    | 14 +++++++++++---
+ include/uapi/linux/usb/ch9.h |  1 +
+ 2 files changed, 12 insertions(+), 3 deletions(-)
+
+diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c
+index b48fac6e4b40..510e7158b502 100644
+--- a/drivers/usb/core/config.c
++++ b/drivers/usb/core/config.c
+@@ -528,15 +528,23 @@ static int usb_parse_configuration(struct usb_device *dev, int cfgidx,
+ 
+                } else if (header->bDescriptorType ==
+                                USB_DT_INTERFACE_ASSOCIATION) {
++                       struct usb_interface_assoc_descriptor *d;
++
++                       d = (struct usb_interface_assoc_descriptor *)header;
++                       if (d->bLength < USB_DT_INTERFACE_ASSOCIATION_SIZE) {
++                               dev_warn(ddev,
++                                        "config %d has an invalid interface association descriptor of length %d, skipping\n",
++                                        cfgno, d->bLength);
++                               continue;
++                       }
++
+                        if (iad_num == USB_MAXIADS) {
+                                dev_warn(ddev, "found more Interface "
+                                               "Association Descriptors "
+                                               "than allocated for in "
+                                               "configuration %d\n", cfgno);
+                        } else {
+-                               config->intf_assoc[iad_num] =
+-                                       (struct usb_interface_assoc_descriptor
+-                                       *)header;
++                               config->intf_assoc[iad_num] = d;
+                                iad_num++;
+                        }
+ 
+diff --git a/include/uapi/linux/usb/ch9.h b/include/uapi/linux/usb/ch9.h
+index aa33fd1b2d4f..400196c45b3c 100644
+--- a/include/uapi/linux/usb/ch9.h
++++ b/include/uapi/linux/usb/ch9.h
+@@ -705,6 +705,7 @@ struct usb_interface_assoc_descriptor {
+        __u8  iFunction;
+ } __attribute__ ((packed));
+ 
++#define USB_DT_INTERFACE_ASSOCIATION_SIZE      8
+ 
+ /*-------------------------------------------------------------------------*/
+ 
+-- 
+cgit 1.2-0.3.lf.el7
+