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[2006-11-10 12:44 UTC] ben at thelemite dot freeserve dot co dot uk
Description:
------------
Executing SELECT * queries on tables that contain 64-bit values (such as bigints) cause a seg fault. Segfault occurs in php_mssql_get_column_content_with_type within php_mssql.c
It's probably system dependent but has been verified on a separate Solaris 10 setup.
Note the following things though:
1) Running queries containing 64-bit fields that do not contain the primary key do not seem to cause the crash, e.g: "SELECT value from TestTable", but individually selecting fields does, e.g: "SELECT id,value". Bizzarely "SELECT value,id" doesn't cause a crash.
2) There seems to be some weird allocation issues going on that I have not been able to get to the bottom of. In php_mssql_get_column_content_with_type there is:
case SQLFLT8:
ZVAL_DOUBLE(result, (double) floatcol8(offset));
break;
If I change it to:
case SQLFLT8:
{
DBFLT8 res_buf;
memcpy(&res_buf, &floatcol8(offset), 8);
ZVAL_DOUBLE(result, res_buf);
}
break;
It cures the problem! But (very bizzarely), the following code still crashes:
res_buf = *(DBFLT8 *)dbdata(mssql_ptr->link,offset);
ZVAL_DOUBLE(result, res_buf);
BUT... It does not crash at the point of reading the data into res_buf. It's crashes when something is done with the value! (Possibly FreeTDS is corrupting the stack?).
Help!
SunOS 5.10 Generic_118833-17 sun4u sparc SUNW,Ultra-60
PHP 5.1.6 (cli) (built: Oct 26 2006 15:30:54) [same on 5.2.0 as well though]
FreeTDS 0.63
Reproduce code:
---------------
Table I have been using for experimenting:-
TestTable {
id, int
value, bigint
}
PHP code to generate crash:-
$link = mssql_connect("MyServer","MyUser","MyPassword");
$q = mssql_query("SELECT * from TestTable");
echo $q;
Expected result:
----------------
Resource id #X
Actual result:
--------------
nothing (segfaults when run from CLI)
PatchesPull RequestsHistoryAllCommentsChangesGit/SVN commits
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Last updated: Sat Dec 21 12:01:31 2024 UTC |
Firstly I seem to have narrowed it down a little further. Crashes only occur when the first 64-bit field occurs in column 2 (as in my test table). If I rearrange the table to something like TestTable { id, int value1, int value2, bigint } suddenly it doesn't crash anymore. very, very weird. anyway, the requested backtrace:- php_mssql_get_column_content_with_type+0x2b8(6c0178, 2, 604998, 3e, 6140d8, 61357c) _mssql_fetch_batch+0x244(0, 6037c8, ffffffff, 0, 2, 523858) zif_mssql_query+0x2a4(2, 604ae0, ffffffff, 6c0178, 2, ffbfed60) zend_do_fcall_common_helper_SPEC+0x6f0(ffbfee08, ffbfee08, 1, 688e20, ffbfee08, 66d9e0) execute+0x10c(6418d8, 40, 523818, ffbff0dc, 168, 748c) zend_do_fcall_common_helper_SPEC+0x204(ffbff1e0, 35ebd8, 1, 6418d8, ffbff1e0, 1) execute+0x10c(689008, 40, 523818, ffbff3b4, 78, 748c) zend_do_fcall_common_helper_SPEC+0x204(ffbff3e0, ffbff3e0, 1, 0, 0, ffbff4a8) execute+0x10c(5fffa0, ffbffc70, 1e8ff0, ffbff4ac, 4, 2279ac) zend_execute_scripts+0xe0(7c54, 0, 3, ffbff598, 523598, ffbffc70) php_execute_script+0x260(ffbffc70, 74, 2d00, 74657374, 0, ffbffa48) main+0xfb8(2, ffbffd0c, ffbffd18, 50bf40, 0, 0) _start+0x5c(0, 0, 0, 0, 0, 0)Hi, is there any solution about this Bug, I'm having the same trouble with this, there is the information of my case: Server: Dell PE 2970 SO: RHEL 5.3 PHP: 5.3 FreeTDS: 0.64 SQL Server: SQL Server 2005 SP2 On Win2003 Here is an example: test_table{ id, int text_field, varchar(10) int_field, int bigint_field, bigint float_field, float } $link = mssql_connect("mssqlServer", "mssqlUser", "mssqlPass"); mssql_select_db("mssqlDb", $link); $version = mssql_query("Select id, text_field, int_field, bigint_field, float_field From test_table"); while($row = mssql_fetch_assoc($version)){ print_r($row); echo "\r\n<br><br>"; } The httpd error_log trowhs: zend_mm_heap corrupted PHP crash when I select the float_field... Thanks in advance...