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
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
|
From bd43c78956040a5d419d5034cdddd4b62c5dd53e Mon Sep 17 00:00:00 2001
From: Andreas Wellving <andreas.wellving@enea.com>
Date: Mon, 22 Oct 2018 10:37:02 +0200
Subject: [PATCH] sunrpc: Avoid use-after-free read access in clntudp_call [BZ #21115]
After commit bc779a1a5b3035133024b21e2f339fe4219fb11c
(CVE-2016-4429: sunrpc: Do not use alloca in clntudp_call
[BZ #20112]), ancillary data is stored on the heap,
but it is accessed after it has been freed.
The test case must be run under a heap debugger such as valgrind
to observe the invalid access. A malloc implementation which
immediately calls munmap on free would catch this bug as well.
This patch is for CVE-2017-12133.
(cherry picked from commit d42eed4a044e5e10dfb885cf9891c2518a72a491)
CVE: CVE-2017-12133
Upstream-Status: Backport [https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=d42eed4a044e5e10dfb885cf9891c2518a72a491]
Signed-off-by: Andreas Wellving <andreas.wellving@enea.com>
---
ChangeLog | 8 +++++++
NEWS | 1 +
sunrpc/Makefile | 3 ++-
sunrpc/clnt_udp.c | 2 +-
sunrpc/tst-udp-error.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 74 insertions(+), 2 deletions(-)
create mode 100644 sunrpc/tst-udp-error.c
diff --git a/ChangeLog b/ChangeLog
index 48b095b..097ab5c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2017-02-27 Florian Weimer <fweimer@redhat.com>
+
+ [BZ #21115]
+ * sunrpc/clnt_udp.c (clntudp_call): Free ancillary data later.
+ * sunrpc/Makefile (tests): Add tst-udp-error.
+ (tst-udp-error): Link against libc.so explicitly.
+ * sunrpc/tst-udp-error: New file.
+
2018-01-18 Arjun Shankar <arjun@redhat.com>
[BZ #22343]
diff --git a/NEWS b/NEWS
index 5134f34..4765e1b 100644
--- a/NEWS
+++ b/NEWS
@@ -376,6 +376,7 @@ The following bugs are resolved with this release:
[21081] string: Missing vzeroupper in memset-vec-unaligned-erms.S
[22343] malloc: Integer overflow in posix_memalign (CVE-2018-6485)
[22774] malloc: Integer overflow in malloc (CVE-2018-6551)
+ [21115] sunrpc: Use-after-free in error path in clntudp_call
Version 2.24
diff --git a/sunrpc/Makefile b/sunrpc/Makefile
index 12ec2e7..8b9f25f 100644
--- a/sunrpc/Makefile
+++ b/sunrpc/Makefile
@@ -93,7 +93,7 @@ rpcgen-objs = rpc_main.o rpc_hout.o rpc_cout.o rpc_parse.o \
extra-objs = $(rpcgen-objs) $(addprefix cross-,$(rpcgen-objs))
others += rpcgen
-tests = tst-xdrmem tst-xdrmem2 test-rpcent tst-xdrmem3
+tests = tst-xdrmem tst-xdrmem2 test-rpcent tst-xdrmem3 tst-udp-error
xtests := tst-getmyaddr
tests-special += $(objpfx)mtrace-tst-xdrmem3.out
@@ -163,6 +163,7 @@ $(objpfx)tst-getmyaddr: $(common-objpfx)linkobj/libc.so
$(objpfx)tst-xdrmem: $(common-objpfx)linkobj/libc.so
$(objpfx)tst-xdrmem2: $(common-objpfx)linkobj/libc.so
(objpfx)tst-xdrmem2: $(common-objpfx)linkobj/libc.so
+$(objpfx)tst-udp-error: $(common-objpfx)linkobj/libc.so
$(objpfx)rpcgen: $(addprefix $(objpfx),$(rpcgen-objs))
diff --git a/sunrpc/clnt_udp.c b/sunrpc/clnt_udp.c
index 4d9acb1..1de25cb 100644
--- a/sunrpc/clnt_udp.c
+++ b/sunrpc/clnt_udp.c
@@ -421,9 +421,9 @@ send_again:
cmsg = CMSG_NXTHDR (&msg, cmsg))
if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_RECVERR)
{
- free (cbuf);
e = (struct sock_extended_err *) CMSG_DATA(cmsg);
cu->cu_error.re_errno = e->ee_errno;
+ free (cbuf);
return (cu->cu_error.re_status = RPC_CANTRECV);
}
free (cbuf);
diff --git a/sunrpc/tst-udp-error.c b/sunrpc/tst-udp-error.c
new file mode 100644
index 0000000..1efc02f
--- /dev/null
+++ b/sunrpc/tst-udp-error.c
@@ -0,0 +1,62 @@
+/* Check for use-after-free in clntudp_call (bug 21115).
+ Copyright (C) 2017 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <netinet/in.h>
+#include <rpc/clnt.h>
+#include <rpc/svc.h>
+#include <support/check.h>
+#include <support/namespace.h>
+#include <support/xsocket.h>
+#include <unistd.h>
+
+static int
+do_test (void)
+{
+ support_become_root ();
+ support_enter_network_namespace ();
+
+ /* Obtain a likely-unused port number. */
+ struct sockaddr_in sin =
+ {
+ .sin_family = AF_INET,
+ .sin_addr.s_addr = htonl (INADDR_LOOPBACK),
+ };
+ {
+ int fd = xsocket (AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
+ xbind (fd, (struct sockaddr *) &sin, sizeof (sin));
+ socklen_t sinlen = sizeof (sin);
+ xgetsockname (fd, (struct sockaddr *) &sin, &sinlen);
+ /* Close the socket, so that we will receive an error below. */
+ close (fd);
+ }
+
+ int sock = RPC_ANYSOCK;
+ CLIENT *clnt = clntudp_create
+ (&sin, 1, 2, (struct timeval) { 1, 0 }, &sock);
+ TEST_VERIFY_EXIT (clnt != NULL);
+ TEST_VERIFY (clnt_call (clnt, 3,
+ (xdrproc_t) xdr_void, NULL,
+ (xdrproc_t) xdr_void, NULL,
+ ((struct timeval) { 3, 0 }))
+ == RPC_CANTRECV);
+ clnt_destroy (clnt);
+
+ return 0;
+}
+
+#include <support/test-driver.c>
|
