-
Notifications
You must be signed in to change notification settings - Fork 493
/
0066-iconv-ISO-2022-CN-EXT-fix-out-of-bound-writes-when-w.patch
216 lines (209 loc) · 6.99 KB
/
0066-iconv-ISO-2022-CN-EXT-fix-out-of-bound-writes-when-w.patch
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
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
From e1135387deded5d73924f6ca20c72a35dc8e1bda Mon Sep 17 00:00:00 2001
From: Charles Fol <folcharles@gmail.com>
Date: Thu, 28 Mar 2024 12:25:38 -0300
Subject: [PATCH] iconv: ISO-2022-CN-EXT: fix out-of-bound writes when writing
escape sequence (CVE-2024-2961)
ISO-2022-CN-EXT uses escape sequences to indicate character set changes
(as specified by RFC 1922). While the SOdesignation has the expected
bounds checks, neither SS2designation nor SS3designation have its;
allowing a write overflow of 1, 2, or 3 bytes with fixed values:
'$+I', '$+J', '$+K', '$+L', '$+M', or '$*H'.
Checked on aarch64-linux-gnu.
Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit f9dc609e06b1136bb0408be9605ce7973a767ada)
---
iconvdata/Makefile | 5 +-
iconvdata/iso-2022-cn-ext.c | 12 +++
iconvdata/tst-iconv-iso-2022-cn-ext.c | 128 ++++++++++++++++++++++++++
3 files changed, 144 insertions(+), 1 deletion(-)
create mode 100644 iconvdata/tst-iconv-iso-2022-cn-ext.c
diff --git a/iconvdata/Makefile b/iconvdata/Makefile
index dd5cafab21..075098dce8 100644
--- a/iconvdata/Makefile
+++ b/iconvdata/Makefile
@@ -75,7 +75,8 @@ ifeq (yes,$(build-shared))
tests = bug-iconv1 bug-iconv2 tst-loading tst-e2big tst-iconv4 bug-iconv4 \
tst-iconv6 bug-iconv5 bug-iconv6 tst-iconv7 bug-iconv8 bug-iconv9 \
bug-iconv10 bug-iconv11 bug-iconv12 tst-iconv-big5-hkscs-to-2ucs4 \
- bug-iconv13 bug-iconv14 bug-iconv15
+ bug-iconv13 bug-iconv14 bug-iconv15 \
+ tst-iconv-iso-2022-cn-ext
ifeq ($(have-thread-library),yes)
tests += bug-iconv3
endif
@@ -330,6 +331,8 @@ $(objpfx)bug-iconv14.out: $(addprefix $(objpfx), $(gconv-modules)) \
$(addprefix $(objpfx),$(modules.so))
$(objpfx)bug-iconv15.out: $(addprefix $(objpfx), $(gconv-modules)) \
$(addprefix $(objpfx),$(modules.so))
+$(objpfx)tst-iconv-iso-2022-cn-ext.out: $(addprefix $(objpfx), $(gconv-modules)) \
+ $(addprefix $(objpfx),$(modules.so))
$(objpfx)iconv-test.out: run-iconv-test.sh \
$(addprefix $(objpfx), $(gconv-modules)) \
diff --git a/iconvdata/iso-2022-cn-ext.c b/iconvdata/iso-2022-cn-ext.c
index 36727f0865..9bb02238a3 100644
--- a/iconvdata/iso-2022-cn-ext.c
+++ b/iconvdata/iso-2022-cn-ext.c
@@ -574,6 +574,12 @@ DIAG_IGNORE_Os_NEEDS_COMMENT (5, "-Wmaybe-uninitialized");
{ \
const char *escseq; \
\
+ if (outptr + 4 > outend) \
+ { \
+ result = __GCONV_FULL_OUTPUT; \
+ break; \
+ } \
+ \
assert (used == CNS11643_2_set); /* XXX */ \
escseq = "*H"; \
*outptr++ = ESC; \
@@ -587,6 +593,12 @@ DIAG_IGNORE_Os_NEEDS_COMMENT (5, "-Wmaybe-uninitialized");
{ \
const char *escseq; \
\
+ if (outptr + 4 > outend) \
+ { \
+ result = __GCONV_FULL_OUTPUT; \
+ break; \
+ } \
+ \
assert ((used >> 5) >= 3 && (used >> 5) <= 7); \
escseq = "+I+J+K+L+M" + ((used >> 5) - 3) * 2; \
*outptr++ = ESC; \
diff --git a/iconvdata/tst-iconv-iso-2022-cn-ext.c b/iconvdata/tst-iconv-iso-2022-cn-ext.c
new file mode 100644
index 0000000000..96a8765fd5
--- /dev/null
+++ b/iconvdata/tst-iconv-iso-2022-cn-ext.c
@@ -0,0 +1,128 @@
+/* Verify ISO-2022-CN-EXT does not write out of the bounds.
+ Copyright (C) 2024 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
+ <https://www.gnu.org/licenses/>. */
+
+#include <stdio.h>
+#include <string.h>
+
+#include <errno.h>
+#include <iconv.h>
+#include <sys/mman.h>
+
+#include <support/xunistd.h>
+#include <support/check.h>
+#include <support/support.h>
+
+/* The test sets up a two memory page buffer with the second page marked
+ PROT_NONE to trigger a fault if the conversion writes beyond the exact
+ expected amount. Then we carry out various conversions and precisely
+ place the start of the output buffer in order to trigger a SIGSEGV if the
+ process writes anywhere between 1 and page sized bytes more (only one
+ PROT_NONE page is setup as a canary) than expected. These tests exercise
+ all three of the cases in ISO-2022-CN-EXT where the converter must switch
+ character sets and may run out of buffer space while doing the
+ operation. */
+
+static int
+do_test (void)
+{
+ iconv_t cd = iconv_open ("ISO-2022-CN-EXT", "UTF-8");
+ TEST_VERIFY_EXIT (cd != (iconv_t) -1);
+
+ char *ntf;
+ size_t ntfsize;
+ char *outbufbase;
+ {
+ int pgz = getpagesize ();
+ TEST_VERIFY_EXIT (pgz > 0);
+ ntfsize = 2 * pgz;
+
+ ntf = xmmap (NULL, ntfsize, PROT_READ | PROT_WRITE, MAP_PRIVATE
+ | MAP_ANONYMOUS, -1);
+ xmprotect (ntf + pgz, pgz, PROT_NONE);
+
+ outbufbase = ntf + pgz;
+ }
+
+ /* Check if SOdesignation escape sequence does not trigger an OOB write. */
+ {
+ char inbuf[] = "\xe4\xba\xa4\xe6\x8d\xa2";
+
+ for (int i = 0; i < 9; i++)
+ {
+ char *inp = inbuf;
+ size_t inleft = sizeof (inbuf) - 1;
+
+ char *outp = outbufbase - i;
+ size_t outleft = i;
+
+ TEST_VERIFY_EXIT (iconv (cd, &inp, &inleft, &outp, &outleft)
+ == (size_t) -1);
+ TEST_COMPARE (errno, E2BIG);
+
+ TEST_VERIFY_EXIT (iconv (cd, NULL, NULL, NULL, NULL) == 0);
+ }
+ }
+
+ /* Same as before for SS2designation. */
+ {
+ char inbuf[] = "㴽 \xe3\xb4\xbd";
+
+ for (int i = 0; i < 14; i++)
+ {
+ char *inp = inbuf;
+ size_t inleft = sizeof (inbuf) - 1;
+
+ char *outp = outbufbase - i;
+ size_t outleft = i;
+
+ TEST_VERIFY_EXIT (iconv (cd, &inp, &inleft, &outp, &outleft)
+ == (size_t) -1);
+ TEST_COMPARE (errno, E2BIG);
+
+ TEST_VERIFY_EXIT (iconv (cd, NULL, NULL, NULL, NULL) == 0);
+ }
+ }
+
+ /* Same as before for SS3designation. */
+ {
+ char inbuf[] = "劄 \xe5\x8a\x84";
+
+ for (int i = 0; i < 14; i++)
+ {
+ char *inp = inbuf;
+ size_t inleft = sizeof (inbuf) - 1;
+
+ char *outp = outbufbase - i;
+ size_t outleft = i;
+
+ TEST_VERIFY_EXIT (iconv (cd, &inp, &inleft, &outp, &outleft)
+ == (size_t) -1);
+ TEST_COMPARE (errno, E2BIG);
+
+ TEST_VERIFY_EXIT (iconv (cd, NULL, NULL, NULL, NULL) == 0);
+ }
+ }
+
+ TEST_VERIFY_EXIT (iconv_close (cd) != -1);
+
+ xmunmap (ntf, ntfsize);
+
+ return 0;
+}
+
+#include <support/test-driver.c>
--
2.44.0