aboutsummaryrefslogtreecommitdiffstats
path: root/meta/recipes-devtools/git/git-2.3.0/CVE-2015-7545_1.patch
blob: 6bea2268dc570975716a19667510342cf95be900 (plain)
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
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
From a5adaced2e13c135d5d9cc65be9eb95aa3bacedf Mon Sep 17 00:00:00 2001
From: Jeff King <peff@peff.net>
Date: Wed, 16 Sep 2015 13:12:52 -0400
Subject: [PATCH] transport: add a protocol-whitelist environment variable

If we are cloning an untrusted remote repository into a
sandbox, we may also want to fetch remote submodules in
order to get the complete view as intended by the other
side. However, that opens us up to attacks where a malicious
user gets us to clone something they would not otherwise
have access to (this is not necessarily a problem by itself,
but we may then act on the cloned contents in a way that
exposes them to the attacker).

Ideally such a setup would sandbox git entirely away from
high-value items, but this is not always practical or easy
to set up (e.g., OS network controls may block multiple
protocols, and we would want to enable some but not others).

We can help this case by providing a way to restrict
particular protocols. We use a whitelist in the environment.
This is more annoying to set up than a blacklist, but
defaults to safety if the set of protocols git supports
grows). If no whitelist is specified, we continue to default
to allowing all protocols (this is an "unsafe" default, but
since the minority of users will want this sandboxing
effect, it is the only sensible one).

A note on the tests: ideally these would all be in a single
test file, but the git-daemon and httpd test infrastructure
is an all-or-nothing proposition rather than a test-by-test
prerequisite. By putting them all together, we would be
unable to test the file-local code on machines without
apache.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Upstream-Status: Backport
/hom://kernel.googlesource.com/pub/scm/git/git/+/a5adaced2e13c135d5d9cc65be9eb95aa3bacedf%5E%21/
CVE: CVE-2015-7545 patch #1
Signed-off-by: Armin Kuster <akuster@mvista.com>

---
 Documentation/git.txt          | 32 ++++++++++++++
 connect.c                      |  5 +++
 t/lib-proto-disable.sh         | 96 ++++++++++++++++++++++++++++++++++++++++++
 t/t5810-proto-disable-local.sh | 14 ++++++
 t/t5811-proto-disable-git.sh   | 20 +++++++++
 t/t5812-proto-disable-http.sh  | 20 +++++++++
 t/t5813-proto-disable-ssh.sh   | 20 +++++++++
 t/t5814-proto-disable-ext.sh   | 18 ++++++++
 transport-helper.c             |  2 +
 transport.c                    | 21 ++++++++-
 transport.h                    |  7 +++
 11 files changed, 254 insertions(+), 1 deletion(-)
 create mode 100644 t/lib-proto-disable.sh
 create mode 100755 t/t5810-proto-disable-local.sh
 create mode 100755 t/t5811-proto-disable-git.sh
 create mode 100755 t/t5812-proto-disable-http.sh
 create mode 100755 t/t5813-proto-disable-ssh.sh
 create mode 100755 t/t5814-proto-disable-ext.sh

Index: git-2.3.0/Documentation/git.txt
===================================================================
--- git-2.3.0.orig/Documentation/git.txt
+++ git-2.3.0/Documentation/git.txt
@@ -1023,6 +1023,38 @@ GIT_ICASE_PATHSPECS::
 	variable when it is invoked as the top level command by the
 	end user, to be recorded in the body of the reflog.
 
+`GIT_ALLOW_PROTOCOL`::
+	If set, provide a colon-separated list of protocols which are
+	allowed to be used with fetch/push/clone. This is useful to
+	restrict recursive submodule initialization from an untrusted
+	repository. Any protocol not mentioned will be disallowed (i.e.,
+	this is a whitelist, not a blacklist). If the variable is not
+	set at all, all protocols are enabled.  The protocol names
+	currently used by git are:
+
+	  - `file`: any local file-based path (including `file://` URLs,
+	    or local paths)
+
+	  - `git`: the anonymous git protocol over a direct TCP
+	    connection (or proxy, if configured)
+
+	  - `ssh`: git over ssh (including `host:path` syntax,
+	    `git+ssh://`, etc).
+
+	  - `rsync`: git over rsync
+
+	  - `http`: git over http, both "smart http" and "dumb http".
+	    Note that this does _not_ include `https`; if you want both,
+	    you should specify both as `http:https`.
+
+	  - any external helpers are named by their protocol (e.g., use
+	    `hg` to allow the `git-remote-hg` helper)
++
+Note that this controls only git's internal protocol selection.
+If libcurl is used (e.g., by the `http` transport), it may
+redirect to other protocols. There is not currently any way to
+restrict this.
+
 
 Discussion[[Discussion]]
 ------------------------
Index: git-2.3.0/connect.c
===================================================================
--- git-2.3.0.orig/connect.c
+++ git-2.3.0/connect.c
@@ -9,6 +9,7 @@
 #include "url.h"
 #include "string-list.h"
 #include "sha1-array.h"
+#include "transport.h"
 
 static char *server_capabilities;
 static const char *parse_feature_value(const char *, const char *, int *);
@@ -674,6 +675,9 @@ struct child_process *git_connect(int fd
 		 * cannot connect.
 		 */
 		char *target_host = xstrdup(hostandport);
+
+        transport_check_allowed("git");
+
 		if (git_use_proxy(hostandport))
 			conn = git_proxy_connect(fd, hostandport);
 		else
@@ -704,6 +708,7 @@ struct child_process *git_connect(int fd
 			int putty;
 			char *ssh_host = hostandport;
 			const char *port = NULL;
+			transport_check_allowed("ssh");
 			get_host_and_port(&ssh_host, &port);
 			port = get_port_numeric(port);
 
@@ -731,6 +736,7 @@ struct child_process *git_connect(int fd
 			/* remove repo-local variables from the environment */
 			conn->env = local_repo_env;
 			conn->use_shell = 1;
+			transport_check_allowed("file");
 		}
 		argv_array_push(&conn->args, cmd.buf);
 
Index: git-2.3.0/t/lib-proto-disable.sh
===================================================================
--- /dev/null
+++ git-2.3.0/t/lib-proto-disable.sh
@@ -0,0 +1,96 @@
+# Test routines for checking protocol disabling.
+
+# test cloning a particular protocol
+#   $1 - description of the protocol
+#   $2 - machine-readable name of the protocol
+#   $3 - the URL to try cloning
+test_proto () {
+	desc=$1
+	proto=$2
+	url=$3
+
+	test_expect_success "clone $1 (enabled)" '
+		rm -rf tmp.git &&
+		(
+			GIT_ALLOW_PROTOCOL=$proto &&
+			export GIT_ALLOW_PROTOCOL &&
+			git clone --bare "$url" tmp.git
+		)
+	'
+
+	test_expect_success "fetch $1 (enabled)" '
+		(
+			cd tmp.git &&
+			GIT_ALLOW_PROTOCOL=$proto &&
+			export GIT_ALLOW_PROTOCOL &&
+			git fetch
+		)
+	'
+
+	test_expect_success "push $1 (enabled)" '
+		(
+			cd tmp.git &&
+			GIT_ALLOW_PROTOCOL=$proto &&
+			export GIT_ALLOW_PROTOCOL &&
+			git push origin HEAD:pushed
+		)
+	'
+
+	test_expect_success "push $1 (disabled)" '
+		(
+			cd tmp.git &&
+			GIT_ALLOW_PROTOCOL=none &&
+			export GIT_ALLOW_PROTOCOL &&
+			test_must_fail git push origin HEAD:pushed
+		)
+	'
+
+	test_expect_success "fetch $1 (disabled)" '
+		(
+			cd tmp.git &&
+			GIT_ALLOW_PROTOCOL=none &&
+			export GIT_ALLOW_PROTOCOL &&
+			test_must_fail git fetch
+		)
+	'
+
+	test_expect_success "clone $1 (disabled)" '
+		rm -rf tmp.git &&
+		(
+			GIT_ALLOW_PROTOCOL=none &&
+			export GIT_ALLOW_PROTOCOL &&
+			test_must_fail git clone --bare "$url" tmp.git
+		)
+	'
+}
+
+# set up an ssh wrapper that will access $host/$repo in the
+# trash directory, and enable it for subsequent tests.
+setup_ssh_wrapper () {
+	test_expect_success 'setup ssh wrapper' '
+		write_script ssh-wrapper <<-\EOF &&
+		echo >&2 "ssh: $*"
+		host=$1; shift
+		cd "$TRASH_DIRECTORY/$host" &&
+		eval "$*"
+		EOF
+		GIT_SSH="$PWD/ssh-wrapper" &&
+		export GIT_SSH &&
+		export TRASH_DIRECTORY
+	'
+}
+
+# set up a wrapper that can be used with remote-ext to
+# access repositories in the "remote" directory of trash-dir,
+# like "ext::fake-remote %S repo.git"
+setup_ext_wrapper () {
+	test_expect_success 'setup ext wrapper' '
+		write_script fake-remote <<-\EOF &&
+		echo >&2 "fake-remote: $*"
+		cd "$TRASH_DIRECTORY/remote" &&
+		eval "$*"
+		EOF
+		PATH=$TRASH_DIRECTORY:$PATH &&
+		export TRASH_DIRECTORY
+	'
+}
Index: git-2.3.0/t/t5810-proto-disable-local.sh
===================================================================
--- /dev/null
+++ git-2.3.0/t/t5810-proto-disable-local.sh
@@ -0,0 +1,14 @@
+#!/bin/sh
+
+test_description='test disabling of local paths in clone/fetch'
+. ./test-lib.sh
+. "$TEST_DIRECTORY/lib-proto-disable.sh"
+
+test_expect_success 'setup repository to clone' '
+	test_commit one
+'
+
+test_proto "file://" file "file://$PWD"
+test_proto "path" file .
+
+test_done
Index: git-2.3.0/t/t5811-proto-disable-git.sh
===================================================================
--- /dev/null
+++ git-2.3.0/t/t5811-proto-disable-git.sh
@@ -0,0 +1,20 @@
+#!/bin/sh
+
+test_description='test disabling of git-over-tcp in clone/fetch'
+. ./test-lib.sh
+. "$TEST_DIRECTORY/lib-proto-disable.sh"
+. "$TEST_DIRECTORY/lib-git-daemon.sh"
+start_git_daemon
+
+test_expect_success 'create git-accessible repo' '
+	bare="$GIT_DAEMON_DOCUMENT_ROOT_PATH/repo.git" &&
+	test_commit one &&
+	git --bare init "$bare" &&
+	git push "$bare" HEAD &&
+	>"$bare/git-daemon-export-ok" &&
+	git -C "$bare" config daemon.receivepack true
+'
+
+test_proto "git://" git "$GIT_DAEMON_URL/repo.git"
+
+test_done
Index: git-2.3.0/t/t5812-proto-disable-http.sh
===================================================================
--- /dev/null
+++ git-2.3.0/t/t5812-proto-disable-http.sh
@@ -0,0 +1,20 @@
+#!/bin/sh
+
+test_description='test disabling of git-over-http in clone/fetch'
+. ./test-lib.sh
+. "$TEST_DIRECTORY/lib-proto-disable.sh"
+. "$TEST_DIRECTORY/lib-httpd.sh"
+start_httpd
+
+test_expect_success 'create git-accessible repo' '
+	bare="$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+	test_commit one &&
+	git --bare init "$bare" &&
+	git push "$bare" HEAD &&
+	git -C "$bare" config http.receivepack true
+'
+
+test_proto "smart http" http "$HTTPD_URL/smart/repo.git"
+
+stop_httpd
+test_done
Index: git-2.3.0/t/t5813-proto-disable-ssh.sh
===================================================================
--- /dev/null
+++ git-2.3.0/t/t5813-proto-disable-ssh.sh
@@ -0,0 +1,20 @@
+#!/bin/sh
+
+test_description='test disabling of git-over-ssh in clone/fetch'
+. ./test-lib.sh
+. "$TEST_DIRECTORY/lib-proto-disable.sh"
+
+setup_ssh_wrapper
+
+test_expect_success 'setup repository to clone' '
+	test_commit one &&
+	mkdir remote &&
+	git init --bare remote/repo.git &&
+	git push remote/repo.git HEAD
+'
+
+test_proto "host:path" ssh "remote:repo.git"
+test_proto "ssh://" ssh "ssh://remote/$PWD/remote/repo.git"
+test_proto "git+ssh://" ssh "git+ssh://remote/$PWD/remote/repo.git"
+
+test_done
Index: git-2.3.0/t/t5814-proto-disable-ext.sh
===================================================================
--- /dev/null
+++ git-2.3.0/t/t5814-proto-disable-ext.sh
@@ -0,0 +1,18 @@
+#!/bin/sh
+
+test_description='test disabling of remote-helper paths in clone/fetch'
+. ./test-lib.sh
+. "$TEST_DIRECTORY/lib-proto-disable.sh"
+
+setup_ext_wrapper
+
+test_expect_success 'setup repository to clone' '
+	test_commit one &&
+	mkdir remote &&
+	git init --bare remote/repo.git &&
+	git push remote/repo.git HEAD
+'
+
+test_proto "remote-helper" ext "ext::fake-remote %S repo.git"
+
+test_done
Index: git-2.3.0/transport-helper.c
===================================================================
--- git-2.3.0.orig/transport-helper.c
+++ git-2.3.0/transport-helper.c
@@ -1036,6 +1036,8 @@ int transport_helper_init(struct transpo
 	struct helper_data *data = xcalloc(1, sizeof(*data));
 	data->name = name;
 
+	transport_check_allowed(name);
+
 	if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
 		debug = 1;
 
Index: git-2.3.0/transport.c
===================================================================
--- git-2.3.0.orig/transport.c
+++ git-2.3.0/transport.c
@@ -907,6 +907,20 @@ static int external_specification_len(co
 	return strchr(url, ':') - url;
 }
 
+void transport_check_allowed(const char *type)
+{
+	struct string_list allowed = STRING_LIST_INIT_DUP;
+	const char *v = getenv("GIT_ALLOW_PROTOCOL");
+
+	if (!v)
+		return;
+
+	string_list_split(&allowed, v, ':', -1);
+	if (!unsorted_string_list_has_string(&allowed, type))
+		die("transport '%s' not allowed", type);
+	string_list_clear(&allowed, 0);
+}
+
 struct transport *transport_get(struct remote *remote, const char *url)
 {
 	const char *helper;
@@ -938,12 +952,14 @@ struct transport *transport_get(struct r
 	if (helper) {
 		transport_helper_init(ret, helper);
 	} else if (starts_with(url, "rsync:")) {
+		transport_check_allowed("rsync");
 		ret->get_refs_list = get_refs_via_rsync;
 		ret->fetch = fetch_objs_via_rsync;
 		ret->push = rsync_transport_push;
 		ret->smart_options = NULL;
 	} else if (url_is_local_not_ssh(url) && is_file(url) && is_bundle(url, 1)) {
 		struct bundle_transport_data *data = xcalloc(1, sizeof(*data));
+		transport_check_allowed("file");
 		ret->data = data;
 		ret->get_refs_list = get_refs_from_bundle;
 		ret->fetch = fetch_refs_from_bundle;
@@ -955,7 +971,10 @@ struct transport *transport_get(struct r
 		|| starts_with(url, "ssh://")
 		|| starts_with(url, "git+ssh://")
 		|| starts_with(url, "ssh+git://")) {
-		/* These are builtin smart transports. */
+		/*
+		 * These are builtin smart transports; "allowed" transports
+		 * will be checked individually in git_connect.
+		 */
 		struct git_transport_data *data = xcalloc(1, sizeof(*data));
 		ret->data = data;
 		ret->set_option = NULL;
Index: git-2.3.0/transport.h
===================================================================
--- git-2.3.0.orig/transport.h
+++ git-2.3.0/transport.h
@@ -132,6 +132,13 @@ struct transport {
 /* Returns a transport suitable for the url */
 struct transport *transport_get(struct remote *, const char *);
 
+/*
+ * Check whether a transport is allowed by the environment,
+ * and die otherwise. type should generally be the URL scheme,
+ * as described in Documentation/git.txt
+ */
+void transport_check_allowed(const char *type);
+
 /* Transport options which apply to git:// and scp-style URLs */
 
 /* The program to use on the remote side to send a pack */