[OE-core] [ROCKO][PATCH V3 16/34] Qemu: CVE-2018-11806 slirp-heap-buffer-overflow

[Jagadeesh Krishnanjanappa]

From: Jeremy Puhlman <jpuhlman at mvista.com>

slirp: correct size computation while concatenating mbuf

While reassembling incoming fragmented datagrams, 'm_cat' routine
extends the 'mbuf' buffer, if it has insufficient room. It computes
a wrong buffer size, which leads to overwriting adjacent heap buffer
area. Correct this size computation in m_cat.

Affects qemu < 3.0.0

Signed-off-by: Jeremy Puhlman <jpuhlman at mvista.com>
---
 ...018-11806-QEMU-slirp-heap-buffer-overflow.patch | 71 ++++++++++++++++++++++
 meta/recipes-devtools/qemu/qemu_2.10.0.bb          |  1 +
 2 files changed, 72 insertions(+)
 create mode 100644 meta/recipes-devtools/qemu/qemu/0001-CVE-2018-11806-QEMU-slirp-heap-buffer-overflow.patch

diff --git a/meta/recipes-devtools/qemu/qemu/0001-CVE-2018-11806-QEMU-slirp-heap-buffer-overflow.patch b/meta/recipes-devtools/qemu/qemu/0001-CVE-2018-11806-QEMU-slirp-heap-buffer-overflow.patch
new file mode 100644
index 0000000..b3fab26
--- /dev/null
+++ b/meta/recipes-devtools/qemu/qemu/0001-CVE-2018-11806-QEMU-slirp-heap-buffer-overflow.patch
@@ -0,0 +1,71 @@
+From dc21a9d2951f0a2a7e63633e2b5c68c54e4edc4b Mon Sep 17 00:00:00 2001
+From: Jeremy Puhlman <jpuhlman at mvista.com>
+Date: Thu, 14 Jun 2018 01:28:49 +0000
+Subject: [PATCH] QEMU: slirp heap buffer overflow
+
+Subject: [Qemu-devel] [PATCH 1/2] slirp: correct size computation while concatenating mbuf
+Date:	Tue, 5 Jun 2018 23:38:35 +0530
+From: Prasad J Pandit <address at hidden>
+
+While reassembling incoming fragmented datagrams, 'm_cat' routine
+extends the 'mbuf' buffer, if it has insufficient room. It computes
+a wrong buffer size, which leads to overwriting adjacent heap buffer
+area. Correct this size computation in m_cat.
+
+Reported-by: ZDI Disclosures <address at hidden>
+Signed-off-by: Prasad J Pandit <address at hidden>
+
+CVE: CVE-2018-11806
+Upstream-Status: Backport [https://github.com/qemu/qemu/commit/864036e251f54c99d31df124aad7f34f01f5344c#diff-de3b23fd63b9e35d35c454525498d51c]
+
+https://lists.gnu.org/archive/html/qemu-devel/2018-06/msg01012.html
+
+---
+ slirp/mbuf.c | 8 ++++----
+ 1 file changed, 4 insertions(+), 4 deletions(-)
+
+Signed-off-by: Jeremy Puhlman <jpuhlman at mvista.com>
+---
+ slirp/mbuf.c | 8 ++++----
+ 1 file changed, 4 insertions(+), 4 deletions(-)
+
+diff --git a/slirp/mbuf.c b/slirp/mbuf.c
+index 5ff2455..7fb4501 100644
+--- a/slirp/mbuf.c
++++ b/slirp/mbuf.c
+@@ -138,7 +138,7 @@ m_cat(struct mbuf *m, struct mbuf *n)
+ 	 * If there's no room, realloc
+ 	 */
+ 	if (M_FREEROOM(m) < n->m_len)
+-		m_inc(m,m->m_size+MINCSIZE);
++               m_inc(m, m->m_len + n->m_len);
+ 
+ 	memcpy(m->m_data+m->m_len, n->m_data, n->m_len);
+ 	m->m_len += n->m_len;
+@@ -158,12 +158,12 @@ m_inc(struct mbuf *m, int size)
+ 
+         if (m->m_flags & M_EXT) {
+ 	  datasize = m->m_data - m->m_ext;
+-          m->m_ext = g_realloc(m->m_ext, size);
++          m->m_ext = g_realloc(m->m_ext, size + datasize);
+ 	  m->m_data = m->m_ext + datasize;
+         } else {
+ 	  char *dat;
+ 	  datasize = m->m_data - m->m_dat;
+-          dat = g_malloc(size);
++          dat = g_malloc(size + datasize);
+ 	  memcpy(dat, m->m_dat, m->m_size);
+ 
+ 	  m->m_ext = dat;
+@@ -171,7 +171,7 @@ m_inc(struct mbuf *m, int size)
+ 	  m->m_flags |= M_EXT;
+         }
+ 
+-        m->m_size = size;
++        m->m_size = size + datasize;
+ 
+ }
+ 
+-- 
+2.13.3
+
diff --git a/meta/recipes-devtools/qemu/qemu_2.10.0.bb b/meta/recipes-devtools/qemu/qemu_2.10.0.bb
index bdf6c21..89c68f2 100644
--- a/meta/recipes-devtools/qemu/qemu_2.10.0.bb
+++ b/meta/recipes-devtools/qemu/qemu_2.10.0.bb
@@ -30,6 +30,7 @@ SRC_URI = "http://wiki.qemu-project.org/download/${BP}.tar.bz2 \
            file://CVE-2017-14167.patch \
            file://ppc_locking.patch \
            file://memfd.patch \
+           file://0001-CVE-2018-11806-QEMU-slirp-heap-buffer-overflow.patch \
            "
 UPSTREAM_CHECK_REGEX = "qemu-(?P<pver>\d+\..*)\.tar"
 
-- 
2.7.4