1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
|
CVE: CVE-2018-11806
Upstream-Status: Backport
https://lists.gnu.org/archive/html/qemu-devel/2018-06/msg01012.html
From dc21a9d2951f0a2a7e63633e2b5c68c54e4edc4b Mon Sep 17 00:00:00 2001
From: Jeremy Puhlman <jpuhlman@mvista.com>
Date: Thu, 14 Jun 2018 01:28:49 +0000
Subject: [PATCH] CVE-2018-11806 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@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@hidden>
Signed-off-by: Prasad J Pandit <address@hidden>
---
slirp/mbuf.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
Signed-off-by: Jeremy Puhlman <jpuhlman@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
|
