diff options
author | Kai Kang <kai.kang@windriver.com> | 2021-11-18 09:53:36 +0800 |
---|---|---|
committer | Richard Purdie <richard.purdie@linuxfoundation.org> | 2021-11-24 21:12:46 +0000 |
commit | a0745dce6bf173eb72bbaa174d0bf3e172ebb7f5 (patch) | |
tree | c21209c0919c133f122b81bb2dba179b0ee39c59 /meta/recipes-devtools/squashfs-tools/files/CVE-2021-41072.patch | |
parent | 39ee281be1d3e155caf810123cedbf5833ce7045 (diff) | |
download | poky-a0745dce6bf173eb72bbaa174d0bf3e172ebb7f5.tar.gz |
squashfs-tools: fix CVE-2021-41072
Backport patches to fix CVE-2021-41072. And update context for verison
4.4 at same time.
CVE: CVE-2021-41072
Ref:
* https://nvd.nist.gov/vuln/detail/CVE-2021-41072
(From OE-Core rev: e95ccf6f7fe5a42fffcfa5e43087ff964622e26c)
Signed-off-by: Kai Kang <kai.kang@windriver.com>
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Diffstat (limited to 'meta/recipes-devtools/squashfs-tools/files/CVE-2021-41072.patch')
-rw-r--r-- | meta/recipes-devtools/squashfs-tools/files/CVE-2021-41072.patch | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/meta/recipes-devtools/squashfs-tools/files/CVE-2021-41072.patch b/meta/recipes-devtools/squashfs-tools/files/CVE-2021-41072.patch new file mode 100644 index 0000000000..29ec3bbeab --- /dev/null +++ b/meta/recipes-devtools/squashfs-tools/files/CVE-2021-41072.patch | |||
@@ -0,0 +1,316 @@ | |||
1 | CVE: CVE-2021-41072 | ||
2 | Upstream-Status: Backport [https://github.com/plougher/squashfs-tools/commit/e048580] | ||
3 | |||
4 | Backport commit to fix CVE-2021-41072. And squash a follow-up fix for | ||
5 | CVE-2021-41072 from upstream: | ||
6 | https://github.com/plougher/squashfs-tools/commit/19fcc93 | ||
7 | |||
8 | Update context for version 4.4. | ||
9 | |||
10 | Signed-off-by: Kai Kang <kai.kang@windriver.com> | ||
11 | |||
12 | From e0485802ec72996c20026da320650d8362f555bd Mon Sep 17 00:00:00 2001 | ||
13 | From: Phillip Lougher <phillip@squashfs.org.uk> | ||
14 | Date: Sun, 12 Sep 2021 23:50:06 +0100 | ||
15 | Subject: [PATCH] Unsquashfs: additional write outside destination directory | ||
16 | exploit fix | ||
17 | |||
18 | An issue on github (https://github.com/plougher/squashfs-tools/issues/72) | ||
19 | showed how some specially crafted Squashfs filesystems containing | ||
20 | invalid file names (with '/' and '..') can cause Unsquashfs to write | ||
21 | files outside of the destination directory. | ||
22 | |||
23 | Since then it has been shown that specially crafted Squashfs filesystems | ||
24 | that contain a symbolic link pointing outside of the destination directory, | ||
25 | coupled with an identically named file within the same directory, can | ||
26 | cause Unsquashfs to write files outside of the destination directory. | ||
27 | |||
28 | Specifically the symbolic link produces a pathname pointing outside | ||
29 | of the destination directory, which is then followed when writing the | ||
30 | duplicate identically named file within the directory. | ||
31 | |||
32 | This commit fixes this exploit by explictly checking for duplicate | ||
33 | filenames within a directory. As directories in v2.1, v3.x, and v4.0 | ||
34 | filesystems are sorted, this is achieved by checking for consecutively | ||
35 | identical filenames. Additionally directories are checked to | ||
36 | ensure they are sorted, to avoid attempts to evade the duplicate | ||
37 | check. | ||
38 | |||
39 | Version 1.x and 2.0 filesystems (where the directories were unsorted) | ||
40 | are sorted and then the above duplicate filename check is applied. | ||
41 | |||
42 | Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk> | ||
43 | --- | ||
44 | squashfs-tools/Makefile | 6 +- | ||
45 | squashfs-tools/unsquash-1.c | 6 ++ | ||
46 | squashfs-tools/unsquash-12.c | 110 +++++++++++++++++++++++++++++++++ | ||
47 | squashfs-tools/unsquash-1234.c | 21 +++++++ | ||
48 | squashfs-tools/unsquash-2.c | 16 +++++ | ||
49 | squashfs-tools/unsquash-3.c | 6 ++ | ||
50 | squashfs-tools/unsquash-4.c | 6 ++ | ||
51 | squashfs-tools/unsquashfs.h | 4 ++ | ||
52 | 8 files changed, 173 insertions(+), 2 deletions(-) | ||
53 | create mode 100644 squashfs-tools/unsquash-12.c | ||
54 | |||
55 | diff --git a/squashfs-tools/Makefile b/squashfs-tools/Makefile | ||
56 | index 7262a2e..1b544ed 100755 | ||
57 | --- a/squashfs-tools/Makefile | ||
58 | +++ b/squashfs-tools/Makefile | ||
59 | @@ -156,8 +156,8 @@ MKSQUASHFS_OBJS = mksquashfs.o read_fs.o | ||
60 | caches-queues-lists.o | ||
61 | |||
62 | UNSQUASHFS_OBJS = unsquashfs.o unsquash-1.o unsquash-2.o unsquash-3.o \ | ||
63 | - unsquash-4.o unsquash-123.o unsquash-34.o unsquash-1234.o swap.o \ | ||
64 | - compressor.o unsquashfs_info.o | ||
65 | + unsquash-4.o unsquash-123.o unsquash-34.o unsquash-1234.o unsquash-12.o \ | ||
66 | + swap.o compressor.o unsquashfs_info.o | ||
67 | |||
68 | CFLAGS ?= -O2 | ||
69 | CFLAGS += $(EXTRA_CFLAGS) $(INCLUDEDIR) -D_FILE_OFFSET_BITS=64 \ | ||
70 | @@ -353,6 +353,8 @@ unsquash-34.o: unsquashfs.h unsquash-34.c unsquashfs_error.h | ||
71 | |||
72 | unsquash-1234.o: unsquash-1234.c | ||
73 | |||
74 | +unsquash-12.o: unsquash-12.c unsquashfs.h | ||
75 | + | ||
76 | unsquashfs_xattr.o: unsquashfs_xattr.c unsquashfs.h squashfs_fs.h xattr.h | ||
77 | |||
78 | unsquashfs_info.o: unsquashfs.h squashfs_fs.h | ||
79 | --- a/squashfs-tools/unsquash-1.c | ||
80 | +++ b/squashfs-tools/unsquash-1.c | ||
81 | @@ -314,6 +314,12 @@ static struct dir *squashfs_opendir(unsi | ||
82 | } | ||
83 | } | ||
84 | |||
85 | + /* check directory for duplicate names. Need to sort directory first */ | ||
86 | + sort_directory(dir); | ||
87 | + if(check_directory(dir) == FALSE) { | ||
88 | + ERROR("File system corrupted: directory has duplicate names\n"); | ||
89 | + goto corrupted; | ||
90 | + } | ||
91 | return dir; | ||
92 | |||
93 | corrupted: | ||
94 | diff --git a/squashfs-tools/unsquash-12.c b/squashfs-tools/unsquash-12.c | ||
95 | new file mode 100644 | ||
96 | index 0000000..61bf128 | ||
97 | --- /dev/null | ||
98 | +++ b/squashfs-tools/unsquash-12.c | ||
99 | @@ -0,0 +1,110 @@ | ||
100 | +/* | ||
101 | + * Unsquash a squashfs filesystem. This is a highly compressed read only | ||
102 | + * filesystem. | ||
103 | + * | ||
104 | + * Copyright (c) 2021 | ||
105 | + * Phillip Lougher <phillip@squashfs.org.uk> | ||
106 | + * | ||
107 | + * This program is free software; you can redistribute it and/or | ||
108 | + * modify it under the terms of the GNU General Public License | ||
109 | + * as published by the Free Software Foundation; either version 2, | ||
110 | + * or (at your option) any later version. | ||
111 | + * | ||
112 | + * This program is distributed in the hope that it will be useful, | ||
113 | + * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
114 | + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
115 | + * GNU General Public License for more details. | ||
116 | + * | ||
117 | + * You should have received a copy of the GNU General Public License | ||
118 | + * along with this program; if not, write to the Free Software | ||
119 | + * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | ||
120 | + * | ||
121 | + * unsquash-12.c | ||
122 | + * | ||
123 | + * Helper functions used by unsquash-1 and unsquash-2. | ||
124 | + */ | ||
125 | + | ||
126 | +#include "unsquashfs.h" | ||
127 | + | ||
128 | +/* | ||
129 | + * Bottom up linked list merge sort. | ||
130 | + * | ||
131 | + */ | ||
132 | +void sort_directory(struct dir *dir) | ||
133 | +{ | ||
134 | + struct dir_ent *cur, *l1, *l2, *next; | ||
135 | + int len1, len2, stride = 1; | ||
136 | + | ||
137 | + if(dir->dir_count < 2) | ||
138 | + return; | ||
139 | + | ||
140 | + /* | ||
141 | + * We can consider our linked-list to be made up of stride length | ||
142 | + * sublists. Eacn iteration around this loop merges adjacent | ||
143 | + * stride length sublists into larger 2*stride sublists. We stop | ||
144 | + * when stride becomes equal to the entire list. | ||
145 | + * | ||
146 | + * Initially stride = 1 (by definition a sublist of 1 is sorted), and | ||
147 | + * these 1 element sublists are merged into 2 element sublists, which | ||
148 | + * are then merged into 4 element sublists and so on. | ||
149 | + */ | ||
150 | + do { | ||
151 | + l2 = dir->dirs; /* head of current linked list */ | ||
152 | + cur = NULL; /* empty output list */ | ||
153 | + | ||
154 | + /* | ||
155 | + * Iterate through the linked list, merging adjacent sublists. | ||
156 | + * On each interation l2 points to the next sublist pair to be | ||
157 | + * merged (if there's only one sublist left this is simply added | ||
158 | + * to the output list) | ||
159 | + */ | ||
160 | + while(l2) { | ||
161 | + l1 = l2; | ||
162 | + for(len1 = 0; l2 && len1 < stride; len1 ++, l2 = l2->next); | ||
163 | + len2 = stride; | ||
164 | + | ||
165 | + /* | ||
166 | + * l1 points to first sublist. | ||
167 | + * l2 points to second sublist. | ||
168 | + * Merge them onto the output list | ||
169 | + */ | ||
170 | + while(len1 && l2 && len2) { | ||
171 | + if(strcmp(l1->name, l2->name) <= 0) { | ||
172 | + next = l1; | ||
173 | + l1 = l1->next; | ||
174 | + len1 --; | ||
175 | + } else { | ||
176 | + next = l2; | ||
177 | + l2 = l2->next; | ||
178 | + len2 --; | ||
179 | + } | ||
180 | + | ||
181 | + if(cur) { | ||
182 | + cur->next = next; | ||
183 | + cur = next; | ||
184 | + } else | ||
185 | + dir->dirs = cur = next; | ||
186 | + } | ||
187 | + /* | ||
188 | + * One sublist is now empty, copy the other one onto the | ||
189 | + * output list | ||
190 | + */ | ||
191 | + for(; len1; len1 --, l1 = l1->next) { | ||
192 | + if(cur) { | ||
193 | + cur->next = l1; | ||
194 | + cur = l1; | ||
195 | + } else | ||
196 | + dir->dirs = cur = l1; | ||
197 | + } | ||
198 | + for(; l2 && len2; len2 --, l2 = l2->next) { | ||
199 | + if(cur) { | ||
200 | + cur->next = l2; | ||
201 | + cur = l2; | ||
202 | + } else | ||
203 | + dir->dirs = cur = l2; | ||
204 | + } | ||
205 | + } | ||
206 | + cur->next = NULL; | ||
207 | + stride = stride << 1; | ||
208 | + } while(stride < dir->dir_count); | ||
209 | +} | ||
210 | diff --git a/squashfs-tools/unsquash-1234.c b/squashfs-tools/unsquash-1234.c | ||
211 | index e389f8d..98a81ed 100644 | ||
212 | --- a/squashfs-tools/unsquash-1234.c | ||
213 | +++ b/squashfs-tools/unsquash-1234.c | ||
214 | @@ -72,3 +72,24 @@ void squashfs_closedir(struct dir *dir) | ||
215 | |||
216 | free(dir); | ||
217 | } | ||
218 | + | ||
219 | + | ||
220 | +/* | ||
221 | + * Check directory for duplicate names. As the directory should be sorted, | ||
222 | + * duplicates will be consecutive. Obviously we also need to check if the | ||
223 | + * directory has been deliberately unsorted, to evade this check. | ||
224 | + */ | ||
225 | +int check_directory(struct dir *dir) | ||
226 | +{ | ||
227 | + int i; | ||
228 | + struct dir_ent *ent; | ||
229 | + | ||
230 | + if(dir->dir_count < 2) | ||
231 | + return TRUE; | ||
232 | + | ||
233 | + for(ent = dir->dirs, i = 0; i < dir->dir_count - 1; ent = ent->next, i++) | ||
234 | + if(strcmp(ent->name, ent->next->name) >= 0) | ||
235 | + return FALSE; | ||
236 | + | ||
237 | + return TRUE; | ||
238 | +} | ||
239 | diff --git a/squashfs-tools/unsquash-2.c b/squashfs-tools/unsquash-2.c | ||
240 | index 956f96f..0e36f7d 100644 | ||
241 | --- a/squashfs-tools/unsquash-2.c | ||
242 | +++ b/squashfs-tools/unsquash-2.c | ||
243 | @@ -29,6 +29,7 @@ static squashfs_fragment_entry_2 *fragme | ||
244 | static unsigned int *uid_table, *guid_table; | ||
245 | static char *inode_table, *directory_table; | ||
246 | static squashfs_operations ops; | ||
247 | +static int needs_sorting = FALSE; | ||
248 | |||
249 | static void read_block_list(unsigned int *block_list, char *block_ptr, int blocks) | ||
250 | { | ||
251 | @@ -415,6 +416,17 @@ static struct dir *squashfs_opendir(unsi | ||
252 | } | ||
253 | } | ||
254 | |||
255 | + if(needs_sorting) | ||
256 | + sort_directory(dir); | ||
257 | + | ||
258 | + /* check directory for duplicate names and sorting */ | ||
259 | + if(check_directory(dir) == FALSE) { | ||
260 | + if(needs_sorting) | ||
261 | + ERROR("File system corrupted: directory has duplicate names\n"); | ||
262 | + else | ||
263 | + ERROR("File system corrupted: directory has duplicate names or is unsorted\n"); | ||
264 | + goto corrupted; | ||
265 | + } | ||
266 | return dir; | ||
267 | |||
268 | corrupted: | ||
269 | --- a/squashfs-tools/unsquash-3.c | ||
270 | +++ b/squashfs-tools/unsquash-3.c | ||
271 | @@ -442,6 +442,12 @@ static struct dir *squashfs_opendir(unsi | ||
272 | } | ||
273 | } | ||
274 | |||
275 | + /* check directory for duplicate names and sorting */ | ||
276 | + if(check_directory(dir) == FALSE) { | ||
277 | + ERROR("File system corrupted: directory has duplicate names or is unsorted\n"); | ||
278 | + goto corrupted; | ||
279 | + } | ||
280 | + | ||
281 | return dir; | ||
282 | |||
283 | corrupted: | ||
284 | diff --git a/squashfs-tools/unsquash-4.c b/squashfs-tools/unsquash-4.c | ||
285 | index 694783d..c615bb8 100644 | ||
286 | --- a/squashfs-tools/unsquash-4.c | ||
287 | +++ b/squashfs-tools/unsquash-4.c | ||
288 | @@ -378,6 +378,12 @@ static struct dir *squashfs_opendir(unsi | ||
289 | } | ||
290 | } | ||
291 | |||
292 | + /* check directory for duplicate names and sorting */ | ||
293 | + if(check_directory(dir) == FALSE) { | ||
294 | + ERROR("File system corrupted: directory has duplicate names or is unsorted\n"); | ||
295 | + goto corrupted; | ||
296 | + } | ||
297 | + | ||
298 | return dir; | ||
299 | |||
300 | corrupted: | ||
301 | diff --git a/squashfs-tools/unsquashfs.h b/squashfs-tools/unsquashfs.h | ||
302 | index f8cf78c..bf2a80d 100644 | ||
303 | --- a/squashfs-tools/unsquashfs.h | ||
304 | +++ b/squashfs-tools/unsquashfs.h | ||
305 | @@ -266,4 +266,8 @@ extern long long *alloc_index_table(int) | ||
306 | /* unsquash-1234.c */ | ||
307 | extern int check_name(char *, int); | ||
308 | extern void squashfs_closedir(struct dir *); | ||
309 | +extern int check_directory(struct dir *); | ||
310 | + | ||
311 | +/* unsquash-12.c */ | ||
312 | +extern void sort_directory(struct dir *); | ||
313 | #endif | ||
314 | -- | ||
315 | 2.17.1 | ||
316 | |||