https://github.com/json-c/json-c/pull/611 https://github.com/json-c/json-c/commit/74accb17cde1b88794b2b764cabaaf1f0858656c.patch From 74accb17cde1b88794b2b764cabaaf1f0858656c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Esser?= Date: Fri, 15 May 2020 20:38:40 +0200 Subject: [PATCH] Fix CVE-2020-12762. This commit is a squashed and slightly modified backport of the following commits on the master branch: * 77d935b * d07b910 * 519dfe1 * a59d5ac --- linkhash.c | 12 +++++++++++- printbuf.c | 18 +++++++++++++++++- tests/test4.c | 31 ++++++++++++++++++++++++++++++- tests/test4.expected | 1 + 4 files changed, 59 insertions(+), 3 deletions(-) diff --git a/linkhash.c b/linkhash.c index 8791a421e7..6543e171f9 100644 --- a/linkhash.c +++ b/linkhash.c @@ -10,6 +10,7 @@ * */ +#include #include #include #include @@ -431,6 +432,8 @@ struct lh_table* lh_table_new(int size, const char *name, int i; struct lh_table *t; + /* Allocate space for elements to avoid divisions by zero. */ + assert(size > 0); t = (struct lh_table*)calloc(1, sizeof(struct lh_table)); if(!t) lh_abort("lh_table_new: calloc failed\n"); t->count = 0; @@ -495,7 +498,14 @@ int lh_table_insert(struct lh_table *t, void *k, const void *v) unsigned long h, n; t->inserts++; - if(t->count >= t->size * LH_LOAD_FACTOR) lh_table_resize(t, t->size * 2); + if (t->count >= t->size * LH_LOAD_FACTOR) { + /* Avoid signed integer overflow with large tables. */ + int new_size = (t->size > INT_MAX / 2) ? INT_MAX : (t->size * 2); + if (t->size == INT_MAX) + return -1; + + lh_table_resize(t, new_size); + } h = t->hash_fn(k); n = h % t->size; diff --git a/printbuf.c b/printbuf.c index 9d56522000..31dd86f87d 100644 --- a/printbuf.c +++ b/printbuf.c @@ -15,6 +15,7 @@ #include "config.h" +#include #include #include #include @@ -63,7 +64,16 @@ static int printbuf_extend(struct printbuf *p, int min_size) if (p->size >= min_size) return 0; - new_size = json_max(p->size * 2, min_size + 8); + /* Prevent signed integer overflows with large buffers. */ + if (min_size > INT_MAX - 8) + return -1; + if (p->size > INT_MAX / 2) + new_size = min_size + 8; + else { + new_size = p->size * 2; + if (new_size < min_size + 8) + new_size = min_size + 8; + } #ifdef PRINTBUF_DEBUG MC_DEBUG("printbuf_memappend: realloc " "bpos=%d min_size=%d old_size=%d new_size=%d\n", @@ -78,6 +88,9 @@ static int printbuf_extend(struct printbuf *p, int min_size) int printbuf_memappend(struct printbuf *p, const char *buf, int size) { + /* Prevent signed integer overflows with large buffers. */ + if (size > INT_MAX - p->bpos - 1) + return -1; if (p->size <= p->bpos + size + 1) { if (printbuf_extend(p, p->bpos + size + 1) < 0) return -1; @@ -94,6 +107,9 @@ int printbuf_memset(struct printbuf *pb, int offset, int charvalue, int len) if (offset == -1) offset = pb->bpos; + /* Prevent signed integer overflows with large buffers. */ + if (len > INT_MAX - offset) + return -1; size_needed = offset + len; if (pb->size < size_needed) { diff --git a/tests/test4.c b/tests/test4.c index 23e97dac1b..8b05848a13 100644 --- a/tests/test4.c +++ b/tests/test4.c @@ -2,9 +2,11 @@ * gcc -o utf8 utf8.c -I/home/y/include -L./.libs -ljson */ +#include "config.h" +#include #include +#include #include -#include "config.h" #include "json_inttypes.h" #include "json_object.h" @@ -24,6 +26,30 @@ void print_hex( const char* s) printf("\n"); } +static void test_lot_of_adds(void); +static void test_lot_of_adds() +{ + int ii; + char key[50]; + json_object *jobj = json_object_new_object(); + assert(jobj != NULL); + for (ii = 0; ii < 500; ii++) + { + snprintf(key, sizeof(key), "k%d", ii); + json_object *iobj = json_object_new_int(ii); + assert(iobj != NULL); + json_object_object_add(jobj, key, iobj); + if (json_object_object_get_ex(jobj, key, &iobj) == FALSE) + { + fprintf(stderr, "FAILED to add object #%d\n", ii); + abort(); + } + } + printf("%s\n", json_object_to_json_string(jobj)); + assert(json_object_object_length(jobj) == 500); + json_object_put(jobj); +} + int main() { const char *input = "\"\\ud840\\udd26,\\ud840\\udd27,\\ud800\\udd26,\\ud800\\udd27\""; @@ -49,5 +75,8 @@ int main() retval = 1; } json_object_put(parse_result); + + test_lot_of_adds(); + return retval; } diff --git a/tests/test4.expected b/tests/test4.expected index 68d4336d90..cb2744012b 100644 --- a/tests/test4.expected +++ b/tests/test4.expected @@ -1,3 +1,4 @@ input: "\ud840\udd26,\ud840\udd27,\ud800\udd26,\ud800\udd27" JSON parse result is correct: 𠄦,𠄧,𐄦,𐄧 PASS +{ "k0": 0, "k1": 1, "k2": 2, "k3": 3, "k4": 4, "k5": 5, "k6": 6, "k7": 7, "k8": 8, "k9": 9, "k10": 10, "k11": 11, "k12": 12, "k13": 13, "k14": 14, "k15": 15, "k16": 16, "k17": 17, "k18": 18, "k19": 19, "k20": 20, "k21": 21, "k22": 22, "k23": 23, "k24": 24, "k25": 25, "k26": 26, "k27": 27, "k28": 28, "k29": 29, "k30": 30, "k31": 31, "k32": 32, "k33": 33, "k34": 34, "k35": 35, "k36": 36, "k37": 37, "k38": 38, "k39": 39, "k40": 40, "k41": 41, "k42": 42, "k43": 43, "k44": 44, "k45": 45, "k46": 46, "k47": 47, "k48": 48, "k49": 49, "k50": 50, "k51": 51, "k52": 52, "k53": 53, "k54": 54, "k55": 55, "k56": 56, "k57": 57, "k58": 58, "k59": 59, "k60": 60, "k61": 61, "k62": 62, "k63": 63, "k64": 64, "k65": 65, "k66": 66, "k67": 67, "k68": 68, "k69": 69, "k70": 70, "k71": 71, "k72": 72, "k73": 73, "k74": 74, "k75": 75, "k76": 76, "k77": 77, "k78": 78, "k79": 79, "k80": 80, "k81": 81, "k82": 82, "k83": 83, "k84": 84, "k85": 85, "k86": 86, "k87": 87, "k88": 88, "k89": 89, "k90": 90, "k91": 91, "k92": 92, "k93": 93, "k94": 94, "k95": 95, "k96": 96, "k97": 97, "k98": 98, "k99": 99, "k100": 100, "k101": 101, "k102": 102, "k103": 103, "k104": 104, "k105": 105, "k106": 106, "k107": 107, "k108": 108, "k109": 109, "k110": 110, "k111": 111, "k112": 112, "k113": 113, "k114": 114, "k115": 115, "k116": 116, "k117": 117, "k118": 118, "k119": 119, "k120": 120, "k121": 121, "k122": 122, "k123": 123, "k124": 124, "k125": 125, "k126": 126, "k127": 127, "k128": 128, "k129": 129, "k130": 130, "k131": 131, "k132": 132, "k133": 133, "k134": 134, "k135": 135, "k136": 136, "k137": 137, "k138": 138, "k139": 139, "k140": 140, "k141": 141, "k142": 142, "k143": 143, "k144": 144, "k145": 145, "k146": 146, "k147": 147, "k148": 148, "k149": 149, "k150": 150, "k151": 151, "k152": 152, "k153": 153, "k154": 154, "k155": 155, "k156": 156, "k157": 157, "k158": 158, "k159": 159, "k160": 160, "k161": 161, "k162": 162, "k163": 163, "k164": 164, "k165": 165, "k166": 166, "k167": 167, "k168": 168, "k169": 169, "k170": 170, "k171": 171, "k172": 172, "k173": 173, "k174": 174, "k175": 175, "k176": 176, "k177": 177, "k178": 178, "k179": 179, "k180": 180, "k181": 181, "k182": 182, "k183": 183, "k184": 184, "k185": 185, "k186": 186, "k187": 187, "k188": 188, "k189": 189, "k190": 190, "k191": 191, "k192": 192, "k193": 193, "k194": 194, "k195": 195, "k196": 196, "k197": 197, "k198": 198, "k199": 199, "k200": 200, "k201": 201, "k202": 202, "k203": 203, "k204": 204, "k205": 205, "k206": 206, "k207": 207, "k208": 208, "k209": 209, "k210": 210, "k211": 211, "k212": 212, "k213": 213, "k214": 214, "k215": 215, "k216": 216, "k217": 217, "k218": 218, "k219": 219, "k220": 220, "k221": 221, "k222": 222, "k223": 223, "k224": 224, "k225": 225, "k226": 226, "k227": 227, "k228": 228, "k229": 229, "k230": 230, "k231": 231, "k232": 232, "k233": 233, "k234": 234, "k235": 235, "k236": 236, "k237": 237, "k238": 238, "k239": 239, "k240": 240, "k241": 241, "k242": 242, "k243": 243, "k244": 244, "k245": 245, "k246": 246, "k247": 247, "k248": 248, "k249": 249, "k250": 250, "k251": 251, "k252": 252, "k253": 253, "k254": 254, "k255": 255, "k256": 256, "k257": 257, "k258": 258, "k259": 259, "k260": 260, "k261": 261, "k262": 262, "k263": 263, "k264": 264, "k265": 265, "k266": 266, "k267": 267, "k268": 268, "k269": 269, "k270": 270, "k271": 271, "k272": 272, "k273": 273, "k274": 274, "k275": 275, "k276": 276, "k277": 277, "k278": 278, "k279": 279, "k280": 280, "k281": 281, "k282": 282, "k283": 283, "k284": 284, "k285": 285, "k286": 286, "k287": 287, "k288": 288, "k289": 289, "k290": 290, "k291": 291, "k292": 292, "k293": 293, "k294": 294, "k295": 295, "k296": 296, "k297": 297, "k298": 298, "k299": 299, "k300": 300, "k301": 301, "k302": 302, "k303": 303, "k304": 304, "k305": 305, "k306": 306, "k307": 307, "k308": 308, "k309": 309, "k310": 310, "k311": 311, "k312": 312, "k313": 313, "k314": 314, "k315": 315, "k316": 316, "k317": 317, "k318": 318, "k319": 319, "k320": 320, "k321": 321, "k322": 322, "k323": 323, "k324": 324, "k325": 325, "k326": 326, "k327": 327, "k328": 328, "k329": 329, "k330": 330, "k331": 331, "k332": 332, "k333": 333, "k334": 334, "k335": 335, "k336": 336, "k337": 337, "k338": 338, "k339": 339, "k340": 340, "k341": 341, "k342": 342, "k343": 343, "k344": 344, "k345": 345, "k346": 346, "k347": 347, "k348": 348, "k349": 349, "k350": 350, "k351": 351, "k352": 352, "k353": 353, "k354": 354, "k355": 355, "k356": 356, "k357": 357, "k358": 358, "k359": 359, "k360": 360, "k361": 361, "k362": 362, "k363": 363, "k364": 364, "k365": 365, "k366": 366, "k367": 367, "k368": 368, "k369": 369, "k370": 370, "k371": 371, "k372": 372, "k373": 373, "k374": 374, "k375": 375, "k376": 376, "k377": 377, "k378": 378, "k379": 379, "k380": 380, "k381": 381, "k382": 382, "k383": 383, "k384": 384, "k385": 385, "k386": 386, "k387": 387, "k388": 388, "k389": 389, "k390": 390, "k391": 391, "k392": 392, "k393": 393, "k394": 394, "k395": 395, "k396": 396, "k397": 397, "k398": 398, "k399": 399, "k400": 400, "k401": 401, "k402": 402, "k403": 403, "k404": 404, "k405": 405, "k406": 406, "k407": 407, "k408": 408, "k409": 409, "k410": 410, "k411": 411, "k412": 412, "k413": 413, "k414": 414, "k415": 415, "k416": 416, "k417": 417, "k418": 418, "k419": 419, "k420": 420, "k421": 421, "k422": 422, "k423": 423, "k424": 424, "k425": 425, "k426": 426, "k427": 427, "k428": 428, "k429": 429, "k430": 430, "k431": 431, "k432": 432, "k433": 433, "k434": 434, "k435": 435, "k436": 436, "k437": 437, "k438": 438, "k439": 439, "k440": 440, "k441": 441, "k442": 442, "k443": 443, "k444": 444, "k445": 445, "k446": 446, "k447": 447, "k448": 448, "k449": 449, "k450": 450, "k451": 451, "k452": 452, "k453": 453, "k454": 454, "k455": 455, "k456": 456, "k457": 457, "k458": 458, "k459": 459, "k460": 460, "k461": 461, "k462": 462, "k463": 463, "k464": 464, "k465": 465, "k466": 466, "k467": 467, "k468": 468, "k469": 469, "k470": 470, "k471": 471, "k472": 472, "k473": 473, "k474": 474, "k475": 475, "k476": 476, "k477": 477, "k478": 478, "k479": 479, "k480": 480, "k481": 481, "k482": 482, "k483": 483, "k484": 484, "k485": 485, "k486": 486, "k487": 487, "k488": 488, "k489": 489, "k490": 490, "k491": 491, "k492": 492, "k493": 493, "k494": 494, "k495": 495, "k496": 496, "k497": 497, "k498": 498, "k499": 499 }