diff options
author | Ross Burton <ross@burtonini.com> | 2022-03-29 14:07:41 +0100 |
---|---|---|
committer | Richard Purdie <richard.purdie@linuxfoundation.org> | 2022-04-21 21:26:01 +0100 |
commit | f36e87ec4f6e2d45533001b8c4b39d72501a3b5e (patch) | |
tree | de904e6ce0de2b5c64debf5d11b4e00df7ce309b /meta/recipes-core/zlib/zlib/CVE-2018-25032.patch | |
parent | 170ce893e750630a9180ac0ae087b8105418db05 (diff) | |
download | poky-f36e87ec4f6e2d45533001b8c4b39d72501a3b5e.tar.gz |
zlib: backport the fix for CVE-2018-25032
(From OE-Core rev: 27385658aa552b287c4f8f4585f9c783db834123)
Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Diffstat (limited to 'meta/recipes-core/zlib/zlib/CVE-2018-25032.patch')
-rw-r--r-- | meta/recipes-core/zlib/zlib/CVE-2018-25032.patch | 347 |
1 files changed, 347 insertions, 0 deletions
diff --git a/meta/recipes-core/zlib/zlib/CVE-2018-25032.patch b/meta/recipes-core/zlib/zlib/CVE-2018-25032.patch new file mode 100644 index 0000000000..5cb6183641 --- /dev/null +++ b/meta/recipes-core/zlib/zlib/CVE-2018-25032.patch | |||
@@ -0,0 +1,347 @@ | |||
1 | CVE: CVE-2018-25032 | ||
2 | Upstream-Status: Backport | ||
3 | Signed-off-by: Ross Burton <ross.burton@arm.com> | ||
4 | |||
5 | From 5c44459c3b28a9bd3283aaceab7c615f8020c531 Mon Sep 17 00:00:00 2001 | ||
6 | From: Mark Adler <madler@alumni.caltech.edu> | ||
7 | Date: Tue, 17 Apr 2018 22:09:22 -0700 | ||
8 | Subject: [PATCH] Fix a bug that can crash deflate on some input when using | ||
9 | Z_FIXED. | ||
10 | |||
11 | This bug was reported by Danilo Ramos of Eideticom, Inc. It has | ||
12 | lain in wait 13 years before being found! The bug was introduced | ||
13 | in zlib 1.2.2.2, with the addition of the Z_FIXED option. That | ||
14 | option forces the use of fixed Huffman codes. For rare inputs with | ||
15 | a large number of distant matches, the pending buffer into which | ||
16 | the compressed data is written can overwrite the distance symbol | ||
17 | table which it overlays. That results in corrupted output due to | ||
18 | invalid distances, and can result in out-of-bound accesses, | ||
19 | crashing the application. | ||
20 | |||
21 | The fix here combines the distance buffer and literal/length | ||
22 | buffers into a single symbol buffer. Now three bytes of pending | ||
23 | buffer space are opened up for each literal or length/distance | ||
24 | pair consumed, instead of the previous two bytes. This assures | ||
25 | that the pending buffer cannot overwrite the symbol table, since | ||
26 | the maximum fixed code compressed length/distance is 31 bits, and | ||
27 | since there are four bytes of pending space for every three bytes | ||
28 | of symbol space. | ||
29 | --- | ||
30 | deflate.c | 74 ++++++++++++++++++++++++++++++++++++++++--------------- | ||
31 | deflate.h | 25 +++++++++---------- | ||
32 | trees.c | 50 +++++++++++-------------------------- | ||
33 | 3 files changed, 79 insertions(+), 70 deletions(-) | ||
34 | |||
35 | diff --git a/deflate.c b/deflate.c | ||
36 | index 425babc00..19cba873a 100644 | ||
37 | --- a/deflate.c | ||
38 | +++ b/deflate.c | ||
39 | @@ -255,11 +255,6 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy, | ||
40 | int wrap = 1; | ||
41 | static const char my_version[] = ZLIB_VERSION; | ||
42 | |||
43 | - ushf *overlay; | ||
44 | - /* We overlay pending_buf and d_buf+l_buf. This works since the average | ||
45 | - * output size for (length,distance) codes is <= 24 bits. | ||
46 | - */ | ||
47 | - | ||
48 | if (version == Z_NULL || version[0] != my_version[0] || | ||
49 | stream_size != sizeof(z_stream)) { | ||
50 | return Z_VERSION_ERROR; | ||
51 | @@ -329,9 +324,47 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy, | ||
52 | |||
53 | s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ | ||
54 | |||
55 | - overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2); | ||
56 | - s->pending_buf = (uchf *) overlay; | ||
57 | - s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L); | ||
58 | + /* We overlay pending_buf and sym_buf. This works since the average size | ||
59 | + * for length/distance pairs over any compressed block is assured to be 31 | ||
60 | + * bits or less. | ||
61 | + * | ||
62 | + * Analysis: The longest fixed codes are a length code of 8 bits plus 5 | ||
63 | + * extra bits, for lengths 131 to 257. The longest fixed distance codes are | ||
64 | + * 5 bits plus 13 extra bits, for distances 16385 to 32768. The longest | ||
65 | + * possible fixed-codes length/distance pair is then 31 bits total. | ||
66 | + * | ||
67 | + * sym_buf starts one-fourth of the way into pending_buf. So there are | ||
68 | + * three bytes in sym_buf for every four bytes in pending_buf. Each symbol | ||
69 | + * in sym_buf is three bytes -- two for the distance and one for the | ||
70 | + * literal/length. As each symbol is consumed, the pointer to the next | ||
71 | + * sym_buf value to read moves forward three bytes. From that symbol, up to | ||
72 | + * 31 bits are written to pending_buf. The closest the written pending_buf | ||
73 | + * bits gets to the next sym_buf symbol to read is just before the last | ||
74 | + * code is written. At that time, 31*(n-2) bits have been written, just | ||
75 | + * after 24*(n-2) bits have been consumed from sym_buf. sym_buf starts at | ||
76 | + * 8*n bits into pending_buf. (Note that the symbol buffer fills when n-1 | ||
77 | + * symbols are written.) The closest the writing gets to what is unread is | ||
78 | + * then n+14 bits. Here n is lit_bufsize, which is 16384 by default, and | ||
79 | + * can range from 128 to 32768. | ||
80 | + * | ||
81 | + * Therefore, at a minimum, there are 142 bits of space between what is | ||
82 | + * written and what is read in the overlain buffers, so the symbols cannot | ||
83 | + * be overwritten by the compressed data. That space is actually 139 bits, | ||
84 | + * due to the three-bit fixed-code block header. | ||
85 | + * | ||
86 | + * That covers the case where either Z_FIXED is specified, forcing fixed | ||
87 | + * codes, or when the use of fixed codes is chosen, because that choice | ||
88 | + * results in a smaller compressed block than dynamic codes. That latter | ||
89 | + * condition then assures that the above analysis also covers all dynamic | ||
90 | + * blocks. A dynamic-code block will only be chosen to be emitted if it has | ||
91 | + * fewer bits than a fixed-code block would for the same set of symbols. | ||
92 | + * Therefore its average symbol length is assured to be less than 31. So | ||
93 | + * the compressed data for a dynamic block also cannot overwrite the | ||
94 | + * symbols from which it is being constructed. | ||
95 | + */ | ||
96 | + | ||
97 | + s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 4); | ||
98 | + s->pending_buf_size = (ulg)s->lit_bufsize * 4; | ||
99 | |||
100 | if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || | ||
101 | s->pending_buf == Z_NULL) { | ||
102 | @@ -340,8 +373,12 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy, | ||
103 | deflateEnd (strm); | ||
104 | return Z_MEM_ERROR; | ||
105 | } | ||
106 | - s->d_buf = overlay + s->lit_bufsize/sizeof(ush); | ||
107 | - s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize; | ||
108 | + s->sym_buf = s->pending_buf + s->lit_bufsize; | ||
109 | + s->sym_end = (s->lit_bufsize - 1) * 3; | ||
110 | + /* We avoid equality with lit_bufsize*3 because of wraparound at 64K | ||
111 | + * on 16 bit machines and because stored blocks are restricted to | ||
112 | + * 64K-1 bytes. | ||
113 | + */ | ||
114 | |||
115 | s->level = level; | ||
116 | s->strategy = strategy; | ||
117 | @@ -552,7 +589,7 @@ int ZEXPORT deflatePrime (strm, bits, value) | ||
118 | |||
119 | if (deflateStateCheck(strm)) return Z_STREAM_ERROR; | ||
120 | s = strm->state; | ||
121 | - if ((Bytef *)(s->d_buf) < s->pending_out + ((Buf_size + 7) >> 3)) | ||
122 | + if (s->sym_buf < s->pending_out + ((Buf_size + 7) >> 3)) | ||
123 | return Z_BUF_ERROR; | ||
124 | do { | ||
125 | put = Buf_size - s->bi_valid; | ||
126 | @@ -1113,7 +1150,6 @@ int ZEXPORT deflateCopy (dest, source) | ||
127 | #else | ||
128 | deflate_state *ds; | ||
129 | deflate_state *ss; | ||
130 | - ushf *overlay; | ||
131 | |||
132 | |||
133 | if (deflateStateCheck(source) || dest == Z_NULL) { | ||
134 | @@ -1133,8 +1169,7 @@ int ZEXPORT deflateCopy (dest, source) | ||
135 | ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte)); | ||
136 | ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos)); | ||
137 | ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos)); | ||
138 | - overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2); | ||
139 | - ds->pending_buf = (uchf *) overlay; | ||
140 | + ds->pending_buf = (uchf *) ZALLOC(dest, ds->lit_bufsize, 4); | ||
141 | |||
142 | if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL || | ||
143 | ds->pending_buf == Z_NULL) { | ||
144 | @@ -1148,8 +1183,7 @@ int ZEXPORT deflateCopy (dest, source) | ||
145 | zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size); | ||
146 | |||
147 | ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf); | ||
148 | - ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush); | ||
149 | - ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize; | ||
150 | + ds->sym_buf = ds->pending_buf + ds->lit_bufsize; | ||
151 | |||
152 | ds->l_desc.dyn_tree = ds->dyn_ltree; | ||
153 | ds->d_desc.dyn_tree = ds->dyn_dtree; | ||
154 | @@ -1925,7 +1959,7 @@ local block_state deflate_fast(s, flush) | ||
155 | FLUSH_BLOCK(s, 1); | ||
156 | return finish_done; | ||
157 | } | ||
158 | - if (s->last_lit) | ||
159 | + if (s->sym_next) | ||
160 | FLUSH_BLOCK(s, 0); | ||
161 | return block_done; | ||
162 | } | ||
163 | @@ -2056,7 +2090,7 @@ local block_state deflate_slow(s, flush) | ||
164 | FLUSH_BLOCK(s, 1); | ||
165 | return finish_done; | ||
166 | } | ||
167 | - if (s->last_lit) | ||
168 | + if (s->sym_next) | ||
169 | FLUSH_BLOCK(s, 0); | ||
170 | return block_done; | ||
171 | } | ||
172 | @@ -2131,7 +2165,7 @@ local block_state deflate_rle(s, flush) | ||
173 | FLUSH_BLOCK(s, 1); | ||
174 | return finish_done; | ||
175 | } | ||
176 | - if (s->last_lit) | ||
177 | + if (s->sym_next) | ||
178 | FLUSH_BLOCK(s, 0); | ||
179 | return block_done; | ||
180 | } | ||
181 | @@ -2170,7 +2204,7 @@ local block_state deflate_huff(s, flush) | ||
182 | FLUSH_BLOCK(s, 1); | ||
183 | return finish_done; | ||
184 | } | ||
185 | - if (s->last_lit) | ||
186 | + if (s->sym_next) | ||
187 | FLUSH_BLOCK(s, 0); | ||
188 | return block_done; | ||
189 | } | ||
190 | diff --git a/deflate.h b/deflate.h | ||
191 | index 23ecdd312..d4cf1a98b 100644 | ||
192 | --- a/deflate.h | ||
193 | +++ b/deflate.h | ||
194 | @@ -217,7 +217,7 @@ typedef struct internal_state { | ||
195 | /* Depth of each subtree used as tie breaker for trees of equal frequency | ||
196 | */ | ||
197 | |||
198 | - uchf *l_buf; /* buffer for literals or lengths */ | ||
199 | + uchf *sym_buf; /* buffer for distances and literals/lengths */ | ||
200 | |||
201 | uInt lit_bufsize; | ||
202 | /* Size of match buffer for literals/lengths. There are 4 reasons for | ||
203 | @@ -239,13 +239,8 @@ typedef struct internal_state { | ||
204 | * - I can't count above 4 | ||
205 | */ | ||
206 | |||
207 | - uInt last_lit; /* running index in l_buf */ | ||
208 | - | ||
209 | - ushf *d_buf; | ||
210 | - /* Buffer for distances. To simplify the code, d_buf and l_buf have | ||
211 | - * the same number of elements. To use different lengths, an extra flag | ||
212 | - * array would be necessary. | ||
213 | - */ | ||
214 | + uInt sym_next; /* running index in sym_buf */ | ||
215 | + uInt sym_end; /* symbol table full when sym_next reaches this */ | ||
216 | |||
217 | ulg opt_len; /* bit length of current block with optimal trees */ | ||
218 | ulg static_len; /* bit length of current block with static trees */ | ||
219 | @@ -325,20 +320,22 @@ void ZLIB_INTERNAL _tr_stored_block OF((deflate_state *s, charf *buf, | ||
220 | |||
221 | # define _tr_tally_lit(s, c, flush) \ | ||
222 | { uch cc = (c); \ | ||
223 | - s->d_buf[s->last_lit] = 0; \ | ||
224 | - s->l_buf[s->last_lit++] = cc; \ | ||
225 | + s->sym_buf[s->sym_next++] = 0; \ | ||
226 | + s->sym_buf[s->sym_next++] = 0; \ | ||
227 | + s->sym_buf[s->sym_next++] = cc; \ | ||
228 | s->dyn_ltree[cc].Freq++; \ | ||
229 | - flush = (s->last_lit == s->lit_bufsize-1); \ | ||
230 | + flush = (s->sym_next == s->sym_end); \ | ||
231 | } | ||
232 | # define _tr_tally_dist(s, distance, length, flush) \ | ||
233 | { uch len = (uch)(length); \ | ||
234 | ush dist = (ush)(distance); \ | ||
235 | - s->d_buf[s->last_lit] = dist; \ | ||
236 | - s->l_buf[s->last_lit++] = len; \ | ||
237 | + s->sym_buf[s->sym_next++] = dist; \ | ||
238 | + s->sym_buf[s->sym_next++] = dist >> 8; \ | ||
239 | + s->sym_buf[s->sym_next++] = len; \ | ||
240 | dist--; \ | ||
241 | s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \ | ||
242 | s->dyn_dtree[d_code(dist)].Freq++; \ | ||
243 | - flush = (s->last_lit == s->lit_bufsize-1); \ | ||
244 | + flush = (s->sym_next == s->sym_end); \ | ||
245 | } | ||
246 | #else | ||
247 | # define _tr_tally_lit(s, c, flush) flush = _tr_tally(s, 0, c) | ||
248 | diff --git a/trees.c b/trees.c | ||
249 | index 4f4a65011..decaeb7c3 100644 | ||
250 | --- a/trees.c | ||
251 | +++ b/trees.c | ||
252 | @@ -416,7 +416,7 @@ local void init_block(s) | ||
253 | |||
254 | s->dyn_ltree[END_BLOCK].Freq = 1; | ||
255 | s->opt_len = s->static_len = 0L; | ||
256 | - s->last_lit = s->matches = 0; | ||
257 | + s->sym_next = s->matches = 0; | ||
258 | } | ||
259 | |||
260 | #define SMALLEST 1 | ||
261 | @@ -948,7 +948,7 @@ void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last) | ||
262 | |||
263 | Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ", | ||
264 | opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len, | ||
265 | - s->last_lit)); | ||
266 | + s->sym_next / 3)); | ||
267 | |||
268 | if (static_lenb <= opt_lenb) opt_lenb = static_lenb; | ||
269 | |||
270 | @@ -1017,8 +1017,9 @@ int ZLIB_INTERNAL _tr_tally (s, dist, lc) | ||
271 | unsigned dist; /* distance of matched string */ | ||
272 | unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */ | ||
273 | { | ||
274 | - s->d_buf[s->last_lit] = (ush)dist; | ||
275 | - s->l_buf[s->last_lit++] = (uch)lc; | ||
276 | + s->sym_buf[s->sym_next++] = dist; | ||
277 | + s->sym_buf[s->sym_next++] = dist >> 8; | ||
278 | + s->sym_buf[s->sym_next++] = lc; | ||
279 | if (dist == 0) { | ||
280 | /* lc is the unmatched char */ | ||
281 | s->dyn_ltree[lc].Freq++; | ||
282 | @@ -1033,30 +1034,7 @@ int ZLIB_INTERNAL _tr_tally (s, dist, lc) | ||
283 | s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++; | ||
284 | s->dyn_dtree[d_code(dist)].Freq++; | ||
285 | } | ||
286 | - | ||
287 | -#ifdef TRUNCATE_BLOCK | ||
288 | - /* Try to guess if it is profitable to stop the current block here */ | ||
289 | - if ((s->last_lit & 0x1fff) == 0 && s->level > 2) { | ||
290 | - /* Compute an upper bound for the compressed length */ | ||
291 | - ulg out_length = (ulg)s->last_lit*8L; | ||
292 | - ulg in_length = (ulg)((long)s->strstart - s->block_start); | ||
293 | - int dcode; | ||
294 | - for (dcode = 0; dcode < D_CODES; dcode++) { | ||
295 | - out_length += (ulg)s->dyn_dtree[dcode].Freq * | ||
296 | - (5L+extra_dbits[dcode]); | ||
297 | - } | ||
298 | - out_length >>= 3; | ||
299 | - Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ", | ||
300 | - s->last_lit, in_length, out_length, | ||
301 | - 100L - out_length*100L/in_length)); | ||
302 | - if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1; | ||
303 | - } | ||
304 | -#endif | ||
305 | - return (s->last_lit == s->lit_bufsize-1); | ||
306 | - /* We avoid equality with lit_bufsize because of wraparound at 64K | ||
307 | - * on 16 bit machines and because stored blocks are restricted to | ||
308 | - * 64K-1 bytes. | ||
309 | - */ | ||
310 | + return (s->sym_next == s->sym_end); | ||
311 | } | ||
312 | |||
313 | /* =========================================================================== | ||
314 | @@ -1069,13 +1047,14 @@ local void compress_block(s, ltree, dtree) | ||
315 | { | ||
316 | unsigned dist; /* distance of matched string */ | ||
317 | int lc; /* match length or unmatched char (if dist == 0) */ | ||
318 | - unsigned lx = 0; /* running index in l_buf */ | ||
319 | + unsigned sx = 0; /* running index in sym_buf */ | ||
320 | unsigned code; /* the code to send */ | ||
321 | int extra; /* number of extra bits to send */ | ||
322 | |||
323 | - if (s->last_lit != 0) do { | ||
324 | - dist = s->d_buf[lx]; | ||
325 | - lc = s->l_buf[lx++]; | ||
326 | + if (s->sym_next != 0) do { | ||
327 | + dist = s->sym_buf[sx++] & 0xff; | ||
328 | + dist += (unsigned)(s->sym_buf[sx++] & 0xff) << 8; | ||
329 | + lc = s->sym_buf[sx++]; | ||
330 | if (dist == 0) { | ||
331 | send_code(s, lc, ltree); /* send a literal byte */ | ||
332 | Tracecv(isgraph(lc), (stderr," '%c' ", lc)); | ||
333 | @@ -1100,11 +1079,10 @@ local void compress_block(s, ltree, dtree) | ||
334 | } | ||
335 | } /* literal or match pair ? */ | ||
336 | |||
337 | - /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */ | ||
338 | - Assert((uInt)(s->pending) < s->lit_bufsize + 2*lx, | ||
339 | - "pendingBuf overflow"); | ||
340 | + /* Check that the overlay between pending_buf and sym_buf is ok: */ | ||
341 | + Assert(s->pending < s->lit_bufsize + sx, "pendingBuf overflow"); | ||
342 | |||
343 | - } while (lx < s->last_lit); | ||
344 | + } while (sx < s->sym_next); | ||
345 | |||
346 | send_code(s, END_BLOCK, ltree); | ||
347 | } | ||