fix CVE-2016-3955

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

diff --git a/CVE-2016-3955-usbip-fix-potential-out-of-bound-write.patch b/CVE-2016-3955-usbip-fix-potential-out-of-bound-write.patch
new file mode 100644 (file)
index 0000000..d3f9fd0
--- /dev/null
+++ b/CVE-2016-3955-usbip-fix-potential-out-of-bound-write.patch
@@ -0,0 +1,45 @@
+From b348d7dddb6c4fbfc810b7a0626e8ec9e29f7cbb Mon Sep 17 00:00:00 2001
+From: Ignat Korchagin <ignat.korchagin@gmail.com>
+Date: Thu, 17 Mar 2016 18:00:29 +0000
+Subject: USB: usbip: fix potential out-of-bounds write
+
+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 <ignat.korchagin@gmail.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/usb/usbip/usbip_common.c | 11 +++++++++++
+ 1 file changed, 11 insertions(+)
+
+diff --git a/drivers/usb/usbip/usbip_common.c b/drivers/usb/usbip/usbip_common.c
+index facaaf0..e40da77 100644
+--- a/drivers/usb/usbip/usbip_common.c
++++ b/drivers/usb/usbip/usbip_common.c
+@@ -741,6 +741,17 @@ 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);
+-- 
+cgit v0.12
+

diff --git a/Makefile b/Makefile
index 6a26e8a59689a8ad73d7203bbc259f7d3abf2be3..694c01aca45d31b9f859869ab91a2dcd604dfbdc 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -236,6 +236,7 @@ ${KERNEL_SRC}/README ${KERNEL_CFG_ORG}: ${KERNELSRCTAR}
        #cd ${KERNEL_SRC}; patch -p1 <../add-empty-ndo_poll_controller-to-veth.patch
        cd ${KERNEL_SRC}; patch -p1 <../override_for_missing_acs_capabilities.patch
        #cd ${KERNEL_SRC}; patch -p1 <../vhost-net-extend-device-allocation-to-vmalloc.patch
+       cd ${KERNEL_SRC}; patch -p1 <../CVE-2016-3955-usbip-fix-potential-out-of-bound-write.patch
        sed -i ${KERNEL_SRC}/Makefile -e 's/^EXTRAVERSION.*$$/EXTRAVERSION=${EXTRAVERSION}/'
        touch $@