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Istvan Miklos
committed
Add RegExp recursion depth limit
The regexp engine does not have any recursion depth check, thus it can cause problems with various regexps. Added a new build option `--regexp-recursion-limit N` whose default value is 0, which is for unlimited recursion depth. Also added a build-option-test. Fixes #2448 JerryScript-DCO-1.0-Signed-off-by: Istvan Miklos imiklos2@inf.u-szeged.hu
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8 files changed

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‎jerry-core/CMakeLists.txt‎

Lines changed: 7 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -39,6 +39,7 @@ set(FEATURE_SYSTEM_ALLOCATOR OFF CACHE BOOL "Enable system allocator?")
3939
set(FEATURE_VALGRIND OFF CACHE BOOL "Enable Valgrind support?")
4040
set(FEATURE_VM_EXEC_STOP OFF CACHE BOOL "Enable VM execution stopping?")
4141
set(MEM_HEAP_SIZE_KB "512" CACHE STRING "Size of memory heap, in kilobytes")
42+
set(REGEXP_RECURSION_LIMIT "0" CACHE STRING "Limit of regexp recursion depth")
4243

4344
# Option overrides
4445
if(USING_MSVC)
@@ -94,6 +95,7 @@ message(STATUS "FEATURE_SYSTEM_ALLOCATOR " ${FEATURE_SYSTEM_ALLOCATOR})
9495
message(STATUS "FEATURE_VALGRIND " ${FEATURE_VALGRIND})
9596
message(STATUS "FEATURE_VM_EXEC_STOP " ${FEATURE_VM_EXEC_STOP})
9697
message(STATUS "MEM_HEAP_SIZE_KB " ${MEM_HEAP_SIZE_KB})
98+
message(STATUS "REGEXP_RECURSION_LIMIT " ${REGEXP_RECURSION_LIMIT})
9799

98100
# Include directories
99101
set(INCLUDE_CORE_PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/include")
@@ -242,6 +244,11 @@ if(FEATURE_REGEXP_STRICT_MODE)
242244
set(DEFINES_JERRY ${DEFINES_JERRY} ENABLE_REGEXP_STRICT_MODE)
243245
endif()
244246

247+
# RegExp recursion depth limit
248+
if(REGEXP_RECURSION_LIMIT)
249+
set(DEFINES_JERRY ${DEFINES_JERRY} REGEXP_RECURSION_LIMIT=${REGEXP_RECURSION_LIMIT})
250+
endif()
251+
245252
# RegExp byte-code dumps
246253
if(FEATURE_REGEXP_DUMP)
247254
set(DEFINES_JERRY ${DEFINES_JERRY} REGEXP_DUMP_BYTE_CODE)

‎jerry-core/ecma/operations/ecma-regexp-object.c‎

Lines changed: 43 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -63,6 +63,13 @@
6363
*/
6464
#define RE_IS_CAPTURE_GROUP(x) (((x) < RE_OP_NON_CAPTURE_GROUP_START) ? 1 : 0)
6565

66+
/**
67+
* Check RegExp recursion depth limit
68+
*/
69+
#ifdef REGEXP_RECURSION_LIMIT
70+
JERRY_STATIC_ASSERT (REGEXP_RECURSION_LIMIT > 0, regexp_recursion_limit_must_be_greater_than_zero);
71+
#endif /* REGEXP_RECURSION_LIMIT */
72+
6673
/**
6774
* Parse RegExp flags (global, ignoreCase, multiline)
6875
*
@@ -347,6 +354,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
347354
const lit_utf8_byte_t *str_p, /**< input string pointer */
348355
const lit_utf8_byte_t **out_str_p) /**< [out] matching substring iterator */
349356
{
357+
REGEXP_RECURSION_COUNTER_DECREASE_AND_TEST ();
350358
const lit_utf8_byte_t *str_curr_p = str_p;
351359

352360
while (true)
@@ -359,12 +367,14 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
359367
{
360368
JERRY_TRACE_MSG ("Execute RE_OP_MATCH: match\n");
361369
*out_str_p = str_curr_p;
370+
REGEXP_RECURSION_COUNTER_INCREASE ();
362371
return ECMA_VALUE_TRUE; /* match */
363372
}
364373
case RE_OP_CHAR:
365374
{
366375
if (str_curr_p >= re_ctx_p->input_end_p)
367376
{
377+
REGEXP_RECURSION_COUNTER_INCREASE ();
368378
return ECMA_VALUE_FALSE; /* fail */
369379
}
370380

@@ -376,6 +386,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
376386
if (ch1 != ch2)
377387
{
378388
JERRY_TRACE_MSG ("fail\n");
389+
REGEXP_RECURSION_COUNTER_INCREASE ();
379390
return ECMA_VALUE_FALSE; /* fail */
380391
}
381392

@@ -387,6 +398,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
387398
{
388399
if (str_curr_p >= re_ctx_p->input_end_p)
389400
{
401+
REGEXP_RECURSION_COUNTER_INCREASE ();
390402
return ECMA_VALUE_FALSE; /* fail */
391403
}
392404

@@ -396,6 +408,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
396408
if (lit_char_is_line_terminator (ch))
397409
{
398410
JERRY_TRACE_MSG ("fail\n");
411+
REGEXP_RECURSION_COUNTER_INCREASE ();
399412
return ECMA_VALUE_FALSE; /* fail */
400413
}
401414

@@ -415,6 +428,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
415428
if (!(re_ctx_p->flags & RE_FLAG_MULTILINE))
416429
{
417430
JERRY_TRACE_MSG ("fail\n");
431+
REGEXP_RECURSION_COUNTER_INCREASE ();
418432
return ECMA_VALUE_FALSE; /* fail */
419433
}
420434

@@ -425,6 +439,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
425439
}
426440

427441
JERRY_TRACE_MSG ("fail\n");
442+
REGEXP_RECURSION_COUNTER_INCREASE ();
428443
return ECMA_VALUE_FALSE; /* fail */
429444
}
430445
case RE_OP_ASSERT_END:
@@ -440,6 +455,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
440455
if (!(re_ctx_p->flags & RE_FLAG_MULTILINE))
441456
{
442457
JERRY_TRACE_MSG ("fail\n");
458+
REGEXP_RECURSION_COUNTER_INCREASE ();
443459
return ECMA_VALUE_FALSE; /* fail */
444460
}
445461

@@ -450,6 +466,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
450466
}
451467

452468
JERRY_TRACE_MSG ("fail\n");
469+
REGEXP_RECURSION_COUNTER_INCREASE ();
453470
return ECMA_VALUE_FALSE; /* fail */
454471
}
455472
case RE_OP_ASSERT_WORD_BOUNDARY:
@@ -481,6 +498,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
481498
if (is_wordchar_left == is_wordchar_right)
482499
{
483500
JERRY_TRACE_MSG ("fail\n");
501+
REGEXP_RECURSION_COUNTER_INCREASE ();
484502
return ECMA_VALUE_FALSE; /* fail */
485503
}
486504
}
@@ -492,6 +510,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
492510
if (is_wordchar_left != is_wordchar_right)
493511
{
494512
JERRY_TRACE_MSG ("fail\n");
513+
REGEXP_RECURSION_COUNTER_INCREASE ();
495514
return ECMA_VALUE_FALSE; /* fail */
496515
}
497516
}
@@ -546,6 +565,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
546565

547566
if (!ECMA_IS_VALUE_ERROR (match_value))
548567
{
568+
REGEXP_RECURSION_COUNTER_INCREASE ();
549569
if (ecma_is_value_true (match_value))
550570
{
551571
*out_str_p = sub_str_p;
@@ -571,6 +591,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
571591
if (str_curr_p >= re_ctx_p->input_end_p)
572592
{
573593
JERRY_TRACE_MSG ("fail\n");
594+
REGEXP_RECURSION_COUNTER_INCREASE ();
574595
return ECMA_VALUE_FALSE; /* fail */
575596
}
576597

@@ -601,6 +622,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
601622
if (!is_match)
602623
{
603624
JERRY_TRACE_MSG ("fail\n");
625+
REGEXP_RECURSION_COUNTER_INCREASE ();
604626
return ECMA_VALUE_FALSE; /* fail */
605627
}
606628
}
@@ -610,6 +632,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
610632
if (is_match)
611633
{
612634
JERRY_TRACE_MSG ("fail\n");
635+
REGEXP_RECURSION_COUNTER_INCREASE ();
613636
return ECMA_VALUE_FALSE; /* fail */
614637
}
615638
}
@@ -640,6 +663,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
640663
if (str_curr_p >= re_ctx_p->input_end_p)
641664
{
642665
JERRY_TRACE_MSG ("fail\n");
666+
REGEXP_RECURSION_COUNTER_INCREASE ();
643667
return ECMA_VALUE_FALSE; /* fail */
644668
}
645669

@@ -649,6 +673,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
649673
if (ch1 != ch2)
650674
{
651675
JERRY_TRACE_MSG ("fail\n");
676+
REGEXP_RECURSION_COUNTER_INCREASE ();
652677
return ECMA_VALUE_FALSE; /* fail */
653678
}
654679
}
@@ -672,6 +697,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
672697
if (ecma_is_value_true (match_value))
673698
{
674699
*out_str_p = sub_str_p;
700+
REGEXP_RECURSION_COUNTER_INCREASE ();
675701
return match_value; /* match */
676702
}
677703
else if (ECMA_IS_VALUE_ERROR (match_value))
@@ -686,13 +712,15 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
686712
bc_p = old_bc_p;
687713

688714
re_ctx_p->saved_p[RE_GLOBAL_START_IDX] = old_start_p;
715+
REGEXP_RECURSION_COUNTER_INCREASE ();
689716
return ECMA_VALUE_FALSE; /* fail */
690717
}
691718
case RE_OP_SAVE_AND_MATCH:
692719
{
693720
JERRY_TRACE_MSG ("End of pattern is reached: match\n");
694721
re_ctx_p->saved_p[RE_GLOBAL_END_IDX] = str_curr_p;
695722
*out_str_p = str_curr_p;
723+
REGEXP_RECURSION_COUNTER_INCREASE ();
696724
return ECMA_VALUE_TRUE; /* match */
697725
}
698726
case RE_OP_ALTERNATIVE:
@@ -757,6 +785,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
757785
if (ecma_is_value_true (match_value))
758786
{
759787
*out_str_p = sub_str_p;
788+
REGEXP_RECURSION_COUNTER_INCREASE ();
760789
return match_value; /* match */
761790
}
762791
else if (ECMA_IS_VALUE_ERROR (match_value))
@@ -815,6 +844,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
815844
if (ecma_is_value_true (match_value))
816845
{
817846
*out_str_p = sub_str_p;
847+
REGEXP_RECURSION_COUNTER_INCREASE ();
818848
return match_value; /* match */
819849
}
820850
else if (ECMA_IS_VALUE_ERROR (match_value))
@@ -839,6 +869,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
839869
if (ecma_is_value_true (match_value))
840870
{
841871
*out_str_p = sub_str_p;
872+
REGEXP_RECURSION_COUNTER_INCREASE ();
842873
return match_value; /* match */
843874
}
844875
else if (ECMA_IS_VALUE_ERROR (match_value))
@@ -848,6 +879,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
848879
}
849880

850881
re_ctx_p->saved_p[start_idx] = old_start_p;
882+
REGEXP_RECURSION_COUNTER_INCREASE ();
851883
return ECMA_VALUE_FALSE; /* fail */
852884
}
853885
case RE_OP_CAPTURE_NON_GREEDY_GROUP_END:
@@ -893,6 +925,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
893925
if (ecma_is_value_true (match_value))
894926
{
895927
*out_str_p = sub_str_p;
928+
REGEXP_RECURSION_COUNTER_INCREASE ();
896929
return match_value; /* match */
897930
}
898931
else if (ECMA_IS_VALUE_ERROR (match_value))
@@ -941,6 +974,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
941974
if (re_ctx_p->num_of_iterations_p[iter_idx] >= min
942975
&& str_curr_p== re_ctx_p->saved_p[start_idx])
943976
{
977+
REGEXP_RECURSION_COUNTER_INCREASE ();
944978
return ECMA_VALUE_FALSE; /* fail */
945979
}
946980

@@ -962,6 +996,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
962996
if (ecma_is_value_true (match_value))
963997
{
964998
*out_str_p = sub_str_p;
999+
REGEXP_RECURSION_COUNTER_INCREASE ();
9651000
return match_value; /* match */
9661001
}
9671002
else if (ECMA_IS_VALUE_ERROR (match_value))
@@ -986,6 +1021,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
9861021
if (ecma_is_value_true (match_value))
9871022
{
9881023
*out_str_p = sub_str_p;
1024+
REGEXP_RECURSION_COUNTER_INCREASE ();
9891025
return match_value; /* match */
9901026
}
9911027
else if (ECMA_IS_VALUE_ERROR (match_value))
@@ -1007,6 +1043,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
10071043
if (ecma_is_value_true (match_value))
10081044
{
10091045
*out_str_p = sub_str_p;
1046+
REGEXP_RECURSION_COUNTER_INCREASE ();
10101047
return match_value; /* match */
10111048
}
10121049
else if (ECMA_IS_VALUE_ERROR (match_value))
@@ -1018,6 +1055,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
10181055
/* restore if fails */
10191056
re_ctx_p->saved_p[end_idx] = old_end_p;
10201057
re_ctx_p->num_of_iterations_p[iter_idx]--;
1058+
REGEXP_RECURSION_COUNTER_INCREASE ();
10211059
return ECMA_VALUE_FALSE; /* fail */
10221060
}
10231061
case RE_OP_NON_GREEDY_ITERATOR:
@@ -1042,6 +1080,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
10421080
if (ecma_is_value_true (match_value))
10431081
{
10441082
*out_str_p = sub_str_p;
1083+
REGEXP_RECURSION_COUNTER_INCREASE ();
10451084
return match_value; /* match */
10461085
}
10471086
else if (ECMA_IS_VALUE_ERROR (match_value))
@@ -1065,6 +1104,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
10651104
str_curr_p = sub_str_p;
10661105
num_of_iter++;
10671106
}
1107+
REGEXP_RECURSION_COUNTER_INCREASE ();
10681108
return ECMA_VALUE_FALSE; /* fail */
10691109
}
10701110
default:
@@ -1108,6 +1148,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
11081148
if (ecma_is_value_true (match_value))
11091149
{
11101150
*out_str_p = sub_str_p;
1151+
REGEXP_RECURSION_COUNTER_INCREASE ();
11111152
return match_value; /* match */
11121153
}
11131154
else if (ECMA_IS_VALUE_ERROR (match_value))
@@ -1123,6 +1164,7 @@ re_match_regexp (re_matcher_ctx_t *re_ctx_p, /**< RegExp matcher context */
11231164
lit_utf8_read_prev (&str_curr_p);
11241165
num_of_iter--;
11251166
}
1167+
REGEXP_RECURSION_COUNTER_INCREASE ();
11261168
return ECMA_VALUE_FALSE; /* fail */
11271169
}
11281170
}
@@ -1211,6 +1253,7 @@ ecma_regexp_exec_helper (ecma_value_t regexp_value, /**< RegExp object */
12111253
re_ctx.input_start_p = input_curr_p;
12121254
const lit_utf8_byte_t *input_end_p = re_ctx.input_start_p + input_buffer_size;
12131255
re_ctx.input_end_p = input_end_p;
1256+
REGEXP_RECURSION_COUNTER_INIT ();
12141257

12151258
/* 1. Read bytecode header and init regexp matcher context. */
12161259
re_ctx.flags = bc_p->header.status_flags;

‎jerry-core/ecma/operations/ecma-regexp-object.h‎

Lines changed: 30 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -18,6 +18,33 @@
1818

1919
#ifndef CONFIG_DISABLE_REGEXP_BUILTIN
2020

21+
#ifdef REGEXP_RECURSION_LIMIT
22+
/**
23+
* Decrease the recursion counter and test it.
24+
* If the counter reaches the limit of the recursion depth
25+
* it will return with a range error.
26+
*/
27+
#define REGEXP_RECURSION_COUNTER_DECREASE_AND_TEST() \
28+
if (--re_ctx_p->recursion_counter == 0) \
29+
{ \
30+
return ecma_raise_range_error (ECMA_ERR_MSG ("RegExp executor recursion limit is exceeded.")); \
31+
}
32+
33+
/**
34+
* Increase the recursion counter
35+
*/
36+
#define REGEXP_RECURSION_COUNTER_INCREASE() (++re_ctx_p->recursion_counter)
37+
38+
/**
39+
* Set the recursion counter to the max depth of the recursion.
40+
*/
41+
#define REGEXP_RECURSION_COUNTER_INIT() (re_ctx.recursion_counter = REGEXP_RECURSION_LIMIT)
42+
#else /* REGEXP_RECURSION_LIMIT */
43+
#define REGEXP_RECURSION_COUNTER_DECREASE_AND_TEST()
44+
#define REGEXP_RECURSION_COUNTER_INCREASE()
45+
#define REGEXP_RECURSION_COUNTER_INIT()
46+
#endif /* REGEXP_RECURSION_LIMIT */
47+
2148
#include "ecma-globals.h"
2249
#include "re-compiler.h"
2350

@@ -48,6 +75,9 @@ typedef struct
4875
const lit_utf8_byte_t **saved_p; /**< saved result string pointers, ECMA 262 v5, 15.10.2.1, State */
4976
const lit_utf8_byte_t *input_start_p; /**< start of input pattern string */
5077
const lit_utf8_byte_t *input_end_p; /**< end of input pattern string */
78+
#ifdef REGEXP_RECURSION_LIMIT
79+
uint32_t recursion_counter; /**< RegExp recursion counter */
80+
#endif /* REGEXP_RECURSION_LIMIT */
5181
uint32_t num_of_captures; /**< number of capture groups */
5282
uint32_t num_of_non_captures; /**< number of non-capture groups */
5383
uint32_t *num_of_iterations_p; /**< number of iterations */

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