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[2016-11-05 21:50 UTC] stas@php.net
-Status: Open
+Status: Closed
-Assigned To:
+Assigned To: stas
[2016-11-05 21:50 UTC] stas@php.net
[2016-11-11 13:09 UTC] nguyenluan dot vnn at gmail dot com
-Status: Closed
+Status: Assigned
[2016-11-11 13:09 UTC] nguyenluan dot vnn at gmail dot com
[2016-11-11 13:09 UTC] nguyenluan dot vnn at gmail dot com
-Status: Assigned
+Status: Open
[2016-11-11 13:09 UTC] nguyenluan dot vnn at gmail dot com
[2016-11-13 16:11 UTC] ab@php.net
[2016-11-14 11:37 UTC] nguyenluan dot vnn at gmail dot com
-Status: Assigned
+Status: Closed
[2016-11-14 11:37 UTC] nguyenluan dot vnn at gmail dot com
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Copyright © 2001-2025 The PHP GroupAll rights reserved. |
Last updated: Wed Oct 29 04:00:01 2025 UTC |
Description: ------------ In function php_basename: PHPAPI zend_string *php_basename(const char *s, size_t len, char *suffix, size_t sufflen) { char *c, *comp, *cend; size_t inc_len, cnt; int state; zend_string *ret; c = comp = cend = (char*)s; cnt = len; // (1) assign cnt as the flen from SPL_METHOD(SplFileInfo, getExtension) state = 0; while (cnt > 0) { (2) cnt has very big value inc_len = (*c == '\0' ? 1 : php_mblen(c, cnt)); // crash here switch (inc_len) { ... ... c += inc_len; cnt -= inc_len; } quit_loop: ... ... } The index for the while loop is cnt may have very big value (I guess due to sign extension), so when it reach out the length of input string an invalid memory access is happened and causes PHP 7 to crash. Test script: --------------- <?php ini_set('memory_limit', -1); $info = new SplFileInfo('foo.'.str_repeat('a', 0x80001000)); var_dump(strlen($info->getExtension())); ?> Expected result: ---------------- No crash. Actual result: -------------- gdb-peda$ r ../test/string/test.php Starting program: /home/user/Desktop/php-7.0.11/sapi/cli/php ../test/string/test.php [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". [----------------------------------registers-----------------------------------] RAX: 0x7fff6cc00000 ("foo.", 'a' <repeats 196 times>...) RBX: 0x0 RCX: 0x0 RDX: 0x0 RSI: 0xffffffff80001004 RDI: 0x7fff6cc00000 ("foo.", 'a' <repeats 196 times>...) RBP: 0x7fffffffa6a0 --> 0x7fffffffa720 --> 0x7fffffffa770 --> 0x7fffffffa7a0 --> 0x7fffffffa7e0 --> 0x7fffffffa8f0 (--> ...) RSP: 0x7fffffffa640 --> 0x0 RIP: 0x8c85fb (<php_basename+48>: mov rax,QWORD PTR [rbp-0x50]) R8 : 0x158d1c0 --> 0x7fffffffd901 --> 0xc0000000000164d1 R9 : 0x7fffed279090 --> 0xc002000800000002 R10: 0x4 R11: 0x206 R12: 0x445010 (<_start>: xor ebp,ebp) R13: 0x7fffffffe1a0 --> 0x2 R14: 0x7fffed214030 --> 0x7fffed2821e0 --> 0xaafc2c (<ZEND_DO_FCALL_SPEC_HANDLER>: push rbp) R15: 0x7fffed2821e0 --> 0xaafc2c (<ZEND_DO_FCALL_SPEC_HANDLER>: push rbp) EFLAGS: 0x202 (carry parity adjust zero sign trap INTERRUPT direction overflow) [-------------------------------------code-------------------------------------] 0x8c85ef <php_basename+36>: mov QWORD PTR [rbp-0x28],rax 0x8c85f3 <php_basename+40>: mov rax,QWORD PTR [rbp-0x28] 0x8c85f7 <php_basename+44>: mov QWORD PTR [rbp-0x30],rax => 0x8c85fb <php_basename+48>: mov rax,QWORD PTR [rbp-0x50] 0x8c85ff <php_basename+52>: mov QWORD PTR [rbp-0x10],rax 0x8c8603 <php_basename+56>: mov DWORD PTR [rbp-0x38],0x0 0x8c860a <php_basename+63>: jmp 0x8c86d4 <php_basename+265> 0x8c860f <php_basename+68>: mov rax,QWORD PTR [rbp-0x30] [------------------------------------stack-------------------------------------] 0000| 0x7fffffffa640 --> 0x0 0008| 0x7fffffffa648 --> 0x0 0016| 0x7fffffffa650 --> 0xffffffff80001004 0024| 0x7fffffffa658 --> 0x7fff6cc00000 ("foo.", 'a' <repeats 196 times>...) 0032| 0x7fffffffa660 --> 0x158d700 --> 0x70600000001 0040| 0x7fffffffa668 --> 0x158d200 --> 0x700000001 0048| 0x7fffffffa670 --> 0x7fff6cc00000 ("foo.", 'a' <repeats 196 times>...) 0056| 0x7fffffffa678 --> 0x7fff6cc00000 ("foo.", 'a' <repeats 196 times>...) [------------------------------------------------------------------------------] Legend: code, data, rodata, value Breakpoint 3, php_basename ( s=0x7fff6cc00000 "foo.", 'a' <repeats 196 times>..., len=0xffffffff80001004, suffix=0x0, sufflen=0x0) at /home/user/Desktop/php-7.0.11/ext/standard/string.c:1560 1560 cnt = len; gdb-peda$ p len $25 = 0xffffffff80001004 gdb-peda$ n [----------------------------------registers-----------------------------------] RAX: 0xffffffff80001004 RBX: 0x0 RCX: 0x0 RDX: 0x0 RSI: 0xffffffff80001004 RDI: 0x7fff6cc00000 ("foo.", 'a' <repeats 196 times>...) RBP: 0x7fffffffa6a0 --> 0x7fffffffa720 --> 0x7fffffffa770 --> 0x7fffffffa7a0 --> 0x7fffffffa7e0 --> 0x7fffffffa8f0 (--> ...) RSP: 0x7fffffffa640 --> 0x0 RIP: 0x8c8603 (<php_basename+56>: mov DWORD PTR [rbp-0x38],0x0) R8 : 0x158d1c0 --> 0x7fffffffd901 --> 0xc0000000000164d1 R9 : 0x7fffed279090 --> 0xc002000800000002 R10: 0x4 R11: 0x206 R12: 0x445010 (<_start>: xor ebp,ebp) R13: 0x7fffffffe1a0 --> 0x2 R14: 0x7fffed214030 --> 0x7fffed2821e0 --> 0xaafc2c (<ZEND_DO_FCALL_SPEC_HANDLER>: push rbp) R15: 0x7fffed2821e0 --> 0xaafc2c (<ZEND_DO_FCALL_SPEC_HANDLER>: push rbp) EFLAGS: 0x202 (carry parity adjust zero sign trap INTERRUPT direction overflow) [-------------------------------------code-------------------------------------] 0x8c85f7 <php_basename+44>: mov QWORD PTR [rbp-0x30],rax 0x8c85fb <php_basename+48>: mov rax,QWORD PTR [rbp-0x50] 0x8c85ff <php_basename+52>: mov QWORD PTR [rbp-0x10],rax => 0x8c8603 <php_basename+56>: mov DWORD PTR [rbp-0x38],0x0 0x8c860a <php_basename+63>: jmp 0x8c86d4 <php_basename+265> 0x8c860f <php_basename+68>: mov rax,QWORD PTR [rbp-0x30] 0x8c8613 <php_basename+72>: movzx eax,BYTE PTR [rax] 0x8c8616 <php_basename+75>: test al,al [------------------------------------stack-------------------------------------] 0000| 0x7fffffffa640 --> 0x0 0008| 0x7fffffffa648 --> 0x0 0016| 0x7fffffffa650 --> 0xffffffff80001004 0024| 0x7fffffffa658 --> 0x7fff6cc00000 ("foo.", 'a' <repeats 196 times>...) 0032| 0x7fffffffa660 --> 0x158d700 --> 0x70600000001 0040| 0x7fffffffa668 --> 0x158d200 --> 0x700000001 0048| 0x7fffffffa670 --> 0x7fff6cc00000 ("foo.", 'a' <repeats 196 times>...) 0056| 0x7fffffffa678 --> 0x7fff6cc00000 ("foo.", 'a' <repeats 196 times>...) [------------------------------------------------------------------------------] Legend: code, data, rodata, value 1561 state = 0; gdb-peda$ p cnt $26 = 0xffffffff80001004 gdb-peda$ c Continuing. Program received signal SIGSEGV, Segmentation fault. [----------------------------------registers-----------------------------------] RAX: 0x7fffecc02000 RBX: 0x0 RCX: 0x0 RDX: 0xffffffff RSI: 0x1 RDI: 0x7fffffffa5c0 --> 0x7fffffffa620 --> 0x7fffed214030 --> 0x7fffed2821e0 --> 0xaafc2c (<ZEND_DO_FCALL_SPEC_HANDLER>: push rbp) RBP: 0x7fffffffa6a0 --> 0x7fffffffa720 --> 0x7fffffffa770 --> 0x7fffffffa7a0 --> 0x7fffffffa7e0 --> 0x7fffffffa8f0 (--> ...) RSP: 0x7fffffffa640 --> 0x0 RIP: 0x8c8613 (<php_basename+72>: movzx eax,BYTE PTR [rax]) R8 : 0x0 R9 : 0x1 R10: 0x7fffffffa5c8 --> 0x7fffecc01004 --> 0x0 R11: 0x246 R12: 0x445010 (<_start>: xor ebp,ebp) R13: 0x7fffffffe1a0 --> 0x2 R14: 0x7fffed214030 --> 0x7fffed2821e0 --> 0xaafc2c (<ZEND_DO_FCALL_SPEC_HANDLER>: push rbp) R15: 0x7fffed2821e0 --> 0xaafc2c (<ZEND_DO_FCALL_SPEC_HANDLER>: push rbp) EFLAGS: 0x10282 (carry parity adjust zero SIGN trap INTERRUPT direction overflow) [-------------------------------------code-------------------------------------] 0x8c8603 <php_basename+56>: mov DWORD PTR [rbp-0x38],0x0 0x8c860a <php_basename+63>: jmp 0x8c86d4 <php_basename+265> 0x8c860f <php_basename+68>: mov rax,QWORD PTR [rbp-0x30] => 0x8c8613 <php_basename+72>: movzx eax,BYTE PTR [rax] 0x8c8616 <php_basename+75>: test al,al 0x8c8618 <php_basename+77>: je 0x8c8631 <php_basename+102> 0x8c861a <php_basename+79>: mov rdx,QWORD PTR [rbp-0x10] 0x8c861e <php_basename+83>: mov rax,QWORD PTR [rbp-0x30] [------------------------------------stack-------------------------------------] 0000| 0x7fffffffa640 --> 0x0 0008| 0x7fffffffa648 --> 0x0 0016| 0x7fffffffa650 --> 0xffffffff80001004 0024| 0x7fffffffa658 --> 0x7fff6cc00000 ("foo.", 'a' <repeats 196 times>...) 0032| 0x7fffffffa660 --> 0x158d700 --> 0x70600000001 0040| 0x7fffffffa668 --> 0x1 0048| 0x7fffffffa670 --> 0x7fffecc02000 0056| 0x7fffffffa678 --> 0x7fff6cc00000 ("foo.", 'a' <repeats 196 times>...) [------------------------------------------------------------------------------] Legend: code, data, rodata, value Stopped reason: SIGSEGV 0x00000000008c8613 in php_basename ( s=0x7fff6cc00000 "foo.", 'a' <repeats 196 times>..., len=0xffffffff80001004, suffix=0x0, sufflen=0x0) at /home/user/Desktop/php-7.0.11/ext/standard/string.c:1563 1563 inc_len = (*c == '\0' ? 1 : php_mblen(c, cnt)); gdb-peda$ p c $27 = 0x7fffecc02000 <error: Cannot access memory at address 0x7fffecc02000> gdb-peda$ p cnt $28 = 0xfffffffefffff004 gdb-peda$ p s $29 = 0x7fff6cc00000 "foo.", 'a' <repeats 196 times>... gdb-peda$ p c - s $30 = 0x80002000 gdb-peda$ bt #0 0x00000000008c8613 in php_basename ( s=0x7fff6cc00000 "foo.", 'a' <repeats 196 times>..., len=0xffffffff80001004, suffix=0x0, sufflen=0x0) at /home/user/Desktop/php-7.0.11/ext/standard/string.c:1563 #1 0x00000000008447f0 in zim_spl_SplFileInfo_getExtension ( execute_data=0x7fffed2141a0, return_value=0x7fffed214100) at /home/user/Desktop/php-7.0.11/ext/spl/spl_directory.c:936 #2 0x0000000000ab00e1 in ZEND_DO_FCALL_SPEC_HANDLER () at /home/user/Desktop/php-7.0.11/Zend/zend_vm_execute.h:842 #3 0x0000000000aaef61 in execute_ex (ex=0x7fffed214030) at /home/user/Desktop/php-7.0.11/Zend/zend_vm_execute.h:414 #4 0x0000000000aaf072 in zend_execute (op_array=0x7fffed281000, return_value=0x0) at /home/user/Desktop/php-7.0.11/Zend/zend_vm_execute.h:458 #5 0x0000000000a5014b in zend_execute_scripts (type=0x8, retval=0x0, file_count=0x3) at /home/user/Desktop/php-7.0.11/Zend/zend.c:1427 #6 0x00000000009b8557 in php_execute_script (primary_file=0x7fffffffce20) at /home/user/Desktop/php-7.0.11/main/main.c:2494 #7 0x0000000000b18327 in do_cli (argc=0x2, argv=0x146e560) at /home/user/Desktop/php-7.0.11/sapi/cli/php_cli.c:974 #8 0x0000000000b194f5 in main (argc=0x2, argv=0x146e560) at /home/user/Desktop/php-7.0.11/sapi/cli/php_cli.c:1344 #9 0x00007ffff416f830 in __libc_start_main (main=0xb18cea <main>, argc=0x2, argv=0x7fffffffe1a8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffe198) at ../csu/libc-start.c:291 #10 0x0000000000445039 in _start ()