Bug #52843 [Opn->Csd]: Segfault when optional parameters are not passed in to mssql_connect

Edit report at http://bugs.php.net/bug.php?id=52843&edit=1 ID: 52843 Updated by: Felipe@php.net Reported by: clint at ubuntu dot com Summary: Segfault when optional parameters are not passed in to mssql_connect -Status: Open +Status: Closed Type: Bug Package: MSSQL related Operating System: Linux PHP Version: 5.3.3 -Assigned To: +Assigned To: Felipe Block user comment: N New Comment: This bug has been fixed in SVN. 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/. Thank you for the report, and for helping us make PHP better. I've committed a slighty modified patch into 5.3 branch and trunk. Thanks for the patch! Previous Comments: ------------------------------------------------------------------------ [2010-09-15 04:12:48] felipe@php.net Automatic comment from SVN on behalf of felipe Revision: http://svn.php.net/viewvc/?view=revision&amp;revision=303375 Log: - Fixed bug #52843 (Segfault when optional parameters are not passed in to mssql_connect) ------------------------------------------------------------------------ [2010-09-14 22:56:33] clint at ubuntu dot com Description: ------------ This was originally reported in Ubuntu: https://bugs.launchpad.net/ubuntu/+source/php5/+bug/611316 Calling mssql_connect() without all of its string arguments will cause php to segfault. This happens on Ubuntu 10.10 beta, and Ubuntu 10.04. I also compiled php 5.3.3 vanilla with ./configure --with-mssql=/usr, and the script below caused the segfault. The error is in this code around line 575 of ext/mssql/php_mssql.c: char *host = NULL, *user = NULL, *passwd = NULL; int host_len, user_len, passwd_len; zend_bool new_link = 0; char *hashed_details; int hashed_details_length; mssql_link mssql, *mssql_ptr; char buffer[40]; if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "|sssb", &host, &host_len, &user, &user_len, &passwd, &passwd_len, &new_link) == FAILURE) { return; } /* Limit strings to 255 chars to prevent overflow issues in underlying libraries */ if(host_len>255) { host[255] = '\0'; } if(user_len>255) { user[255] = '\0'; } if(passwd_len>255) { passwd[255] = '\0'; } If the optional args are not passed in, the len and host parameters will be unchanged, and so a null pointer dereference may occur (depending on the arbitrary value of the _len variables). Test script: --------------- php -r 'mssql_connect();' Expected result: ---------------- I would expect the program to exit without crashing. Actual result: -------------- ubuntu@domU-12-31-39-03-0D-C3:~/src/php5-5.3.3$ gdb php GNU gdb (GDB) 7.2-ubuntu Copyright (C) 2010 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "i686-linux-gnu". For bug reporting instructions, please see: <http://www.gnu.org/software/gdb/bugs/>... Reading symbols from /usr/bin/php...Reading symbols from /usr/lib/debug/usr/bin/php5...done. done. (gdb) run -r 'mssql_connect();' Starting program: /usr/bin/php -r 'mssql_connect();' [Thread debugging using libthread_db enabled] Program received signal SIGSEGV, Segmentation fault. 0xb75ac357 in php_mssql_do_connect (ht=0, return_value=0x88dadb4, return_value_ptr=0x0, this_ptr=0x0, return_value_used=0, persistent=0) at /home/ubuntu/src/php5-5.3.3/ext/mssql/php_mssql.c:587 587 host[255] = '\0'; (gdb) bt #0 0xb75ac357 in php_mssql_do_connect (ht=0, return_value=0x88dadb4, return_value_ptr=0x0, this_ptr=0x0, return_value_used=0, persistent=0) at /home/ubuntu/src/php5-5.3.3/ext/mssql/php_mssql.c:587 #1 0x083600fa in zend_do_fcall_common_helper_SPEC (execute_data=0x0) at /home/ubuntu/src/php5-5.3.3/Zend/zend_vm_execute.h:316 #2 0x08336bbe in execute (op_array=0x88db2c0) at /home/ubuntu/src/php5- 5.3.3/Zend/zend_vm_execute.h:107 #3 0x08300fc3 in zend_eval_stringl (str=0xbffff474 "mssql_connect();", str_len=16, retval_ptr=0x0, string_name=0x8749440 "Command line code") at /home/ubuntu/src/php5-5.3.3/Zend/zend_execute_API.c:1192 #4 0x08301162 in zend_eval_stringl_ex (str=0xbffff474 "mssql_connect();", str_len=16, retval_ptr=0x0, string_name=0x8749440 "Command line code", handle_exceptions=1) at /home/ubuntu/src/php5- 5.3.3/Zend/zend_execute_API.c:1234 #5 0x083011e3 in zend_eval_string_ex (str=0xbffff474 "mssql_connect();", retval_ptr=0x0, string_name=0x8749440 "Command line code", handle_exceptions=1) at /home/ubuntu/src/php5- 5.3.3/Zend/zend_execute_API.c:1245 #6 0x083a3689 in main (argc=3, argv=0xbffff324) at /home/ubuntu/src/php5- 5.3.3/sapi/cli/php_cli.c:1235 (gdb) ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/bug.php?id=52843&edit=1