[OE-core] [PATCH 2/6] qemu: Security fix CVE-2015-7504

[Armin Kuster]

From: Armin Kuster <akuster at mvista.com>

CVE-2015-7504 Qemu: net: pcnet: heap overflow vulnerability in loopback mode

Signed-off-by: Armin Kuster <akuster at mvista.com>
---
 .../recipes-devtools/qemu/qemu/CVE-2015-7504.patch | 56 ++++++++++++++++++++++
 meta/recipes-devtools/qemu/qemu_2.4.0.bb           |  1 +
 2 files changed, 57 insertions(+)
 create mode 100644 meta/recipes-devtools/qemu/qemu/CVE-2015-7504.patch

diff --git a/meta/recipes-devtools/qemu/qemu/CVE-2015-7504.patch b/meta/recipes-devtools/qemu/qemu/CVE-2015-7504.patch
new file mode 100644
index 0000000..90a7947
--- /dev/null
+++ b/meta/recipes-devtools/qemu/qemu/CVE-2015-7504.patch
@@ -0,0 +1,56 @@
+From 837f21aacf5a714c23ddaadbbc5212f9b661e3f7 Mon Sep 17 00:00:00 2001
+From: Prasad J Pandit <pjp at fedoraproject.org>
+Date: Fri, 20 Nov 2015 11:50:31 +0530
+Subject: [PATCH] net: pcnet: add check to validate receive data
+ size(CVE-2015-7504)
+
+In loopback mode, pcnet_receive routine appends CRC code to the
+receive buffer. If the data size given is same as the buffer size,
+the appended CRC code overwrites 4 bytes after s->buffer. Added a
+check to avoid that.
+
+Reported by: Qinghao Tang <luodalongde at gmail.com>
+Cc: qemu-stable at nongnu.org
+Reviewed-by: Michael S. Tsirkin <mst at redhat.com>
+Signed-off-by: Prasad J Pandit <pjp at fedoraproject.org>
+Signed-off-by: Jason Wang <jasowang at redhat.com>
+
+Upstream-Status: Backport
+
+http://git.qemu.org/?p=qemu.git;a=commit;h=837f21aacf5a714c23ddaadbbc5212f9b661e3f7
+
+CVE: CVE-2015-7504
+[Yocto # 9013]
+
+Signed-off-by: Armin Kuster <akuster at mvista.com>
+
+---
+ hw/net/pcnet.c | 8 +++++---
+ 1 file changed, 5 insertions(+), 3 deletions(-)
+
+Index: qemu-2.4.0/hw/net/pcnet.c
+===================================================================
+--- qemu-2.4.0.orig/hw/net/pcnet.c
++++ qemu-2.4.0/hw/net/pcnet.c
+@@ -1085,7 +1085,7 @@ ssize_t pcnet_receive(NetClientState *nc
+                 uint32_t fcs = ~0;
+                 uint8_t *p = src;
+ 
+-                while (p != &src[size-4])
++                while (p != &src[size])
+                     CRC(fcs, *p++);
+                 crc_err = (*(uint32_t *)p != htonl(fcs));
+             }
+@@ -1234,8 +1234,10 @@ static void pcnet_transmit(PCNetState *s
+         bcnt = 4096 - GET_FIELD(tmd.length, TMDL, BCNT);
+ 
+         /* if multi-tmd packet outsizes s->buffer then skip it silently.
+-           Note: this is not what real hw does */
+-        if (s->xmit_pos + bcnt > sizeof(s->buffer)) {
++         * Note: this is not what real hw does.
++         * Last four bytes of s->buffer are used to store CRC FCS code.
++         */
++        if (s->xmit_pos + bcnt > sizeof(s->buffer) - 4) {
+             s->xmit_pos = -1;
+             goto txdone;
+         }
diff --git a/meta/recipes-devtools/qemu/qemu_2.4.0.bb b/meta/recipes-devtools/qemu/qemu_2.4.0.bb
index fec1061..58ce3b5 100644
--- a/meta/recipes-devtools/qemu/qemu_2.4.0.bb
+++ b/meta/recipes-devtools/qemu/qemu_2.4.0.bb
@@ -11,6 +11,7 @@ SRC_URI += "file://configure-fix-Darwin-target-detection.patch \
             file://smc91c111_fix3.patch \
             file://no-valgrind.patch \
             file://CVE-2015-8504.patch \
+            file://CVE-2015-7504.patch \
            "
 SRC_URI_prepend = "http://wiki.qemu-project.org/download/${BP}.tar.bz2"
 SRC_URI[md5sum] = "186ee8194140a484a455f8e3c74589f4"
-- 
2.3.5