Sec Bug->Bug #73011 [Csd]: integer overflow in fgets cause heap corruption

Edit report at https://bugs.php.net/bug.php?id=73011&edit=1 ID: 73011 Updated by: stas@php.net Reported by: minhrau dot vc dot 365 at gmail dot com Summary: integer overflow in fgets cause heap corruption Status: Closed -Type: Security +Type: Bug Package: Filesystem function related Operating System: ALL PHP Version: 5.6.25 Assigned To: stas Block user comment: N Private report: N Previous Comments: ------------------------------------------------------------------------ [2016-09-13 04:12:13] stas@php.net The fix for this bug has been committed. Snapshots of the sources are packaged every three hours; this change will be in the next snapshot. You can grab the snapshot at http://snaps.php.net/. For Windows: http://windows.php.net/snapshots/ Thank you for the report, and for helping us make PHP better. ------------------------------------------------------------------------ [2016-09-05 05:26:44] minhrau dot vc dot 365 at gmail dot com Patch looks good. can i request cve for this? ------------------------------------------------------------------------ [2016-09-05 05:22:19] stas@php.net The fix is in security repo as aec5ab899f9de6cf11ded9c77b649b34f5fcb643 and in https://gist.github.com/ba06b796489e3c50924f2bb3c99012b0 please verify ------------------------------------------------------------------------ [2016-09-04 11:39:30] minhrau dot vc dot 365 at gmail dot com change the package name ------------------------------------------------------------------------ [2016-09-04 11:37:55] minhrau dot vc dot 365 at gmail dot com Description: ------------ Integer overflow in function fgets lead to heap corruption. Please check comment below: PHPAPI PHP_FUNCTION(fgets) { zval *res; long len = 1024; char *buf = NULL; int argc = ZEND_NUM_ARGS(); size_t line_len = 0; php_stream *stream; if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "r|l", &res, &len) == FAILURE) { RETURN_FALSE; } PHP_STREAM_TO_ZVAL(stream, &res); if (argc == 1) { /* ask streams to give us a buffer of an appropriate size */ buf = php_stream_get_line(stream, NULL, 0, &line_len); //<- return string with size_t length if (buf == NULL) { goto exit_failed; } } else if (argc > 1) { if (len <= 0) { php_error_docref(NULL TSRMLS_CC, E_WARNING, "Length parameter must be greater than 0"); RETURN_FALSE; } buf = ecalloc(len + 1, sizeof(char)); if (php_stream_get_line(stream, buf, len, &line_len) == NULL) { goto exit_failed; } } //didn't check for len > INT_MAX ZVAL_STRINGL(return_value, buf, line_len, 0); Test script: --------------- <?php ini_set('memory_limit', -1); $fd = fopen("/opt/lampp/htdocs/a", "r"); //file a with line > max_int $str1 = fgets($fd); var_dump(strlen($str1)); chunk_split($str1, 11, $str1); ?> Expected result: ---------------- No Crash Actual result: -------------- Starting program: /home/minhrau/PHP-5.6.25/sapi/cli/php ~/phptestcase/testfgets.php [Thread debugging using libthread_db enabled] Using host libthread_db library "/usr/lib/libthread_db.so.1". int(-2147483523) Program received signal SIGSEGV, Segmentation fault. 0x00007ffff10a59a4 in __memmove_avx_unaligned_erms () from /usr/lib/libc.so.6 (gdb) bt #0 0x00007ffff10a59a4 in __memmove_avx_unaligned_erms () from /usr/lib/libc.so.6 #1 0x000000000085c99e in zif_chunk_split (ht=3, return_value=0x7ffff7fa14c0, return_value_ptr=0x7ffff7f6c0d8, this_ptr=0x0, return_value_used=0) at /home/minhrau/PHP-5.6.25/ext/standard/string.c:2218 #2 0x00000000009cca94 in zend_do_fcall_common_helper_SPEC (execute_data=0x7ffff7f6c210) at /home/minhrau/PHP-5.6.25/Zend/zend_vm_execute.h:558 #3 0x00000000009d46c4 in ZEND_DO_FCALL_SPEC_CONST_HANDLER (execute_data=0x7ffff7f6c210) at /home/minhrau/PHP-5.6.25/Zend/zend_vm_execute.h:2602 #4 0x00000000009caf87 in execute_ex (execute_data=0x7ffff7f6c210) at /home/minhrau/PHP-5.6.25/Zend/zend_vm_execute.h:363 #5 0x00000000009cb973 in zend_execute (op_array=0x7ffff7fa08d8) at /home/minhrau/PHP-5.6.25/Zend/zend_vm_execute.h:388 #6 0x0000000000986e73 in zend_execute_scripts (type=8, retval=0x0, file_count=3) at /home/minhrau/PHP-5.6.25/Zend/zend.c:1341 #7 0x00000000008f7dcf in php_execute_script (primary_file=0x7fffffffe2a0) at /home/minhrau/PHP-5.6.25/main/main.c:2613 #8 0x0000000000aa9bf5 in do_cli (argc=2, argv=0x1381960) at /home/minhrau/PHP-5.6.25/sapi/cli/php_cli.c:994 #9 0x0000000000aaac43 in main (argc=2, argv=0x1381960) at /home/minhrau/PHP-5.6.25/sapi/cli/php_cli.c:1378 (gdb) ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=73011&edit=1