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Bug #79250 EG(current_module) NULL during property declaration
Submitted: 2020-02-10 11:21 UTC Modified: 2021-02-21 04:22 UTC
From: KseniMailWOW at gmail dot com Assigned: cmb (profile)
Status: No Feedback Package: Class/Object related
PHP Version: 7.4.3RC1 OS: All (Windows7+)
Private report: No CVE-ID: None
View Developer Edit
 [2020-02-10 11:21 UTC] KseniMailWOW at gmail dot com 
Description:
------------
Semple PHP initialization https://pastebin.com/64XuRa4k

Calling zend_declare_property_* results in an empty memory access error (AV MEMORY READ).

The culprit became empty EG(current_module) In the new procedure is_persistent_class (https://github.com/php/php-src/blob/cb7b21009b951d6a08fa948c775c141f6666204c/Zend/zend_API.c#L3474)

Test script:
---------------
zend_class_entry tmp;
INIT_CLASS_ENTRY(tmp, "Hgyjy", NULL);
return zend_register_internal_class(&tmp);	

Replacing with, works great!!!!!!!!!!!!!!!!!!!!!!!!
static zend_always_inline zend_bool is_persistent_class(zend_class_entry *ce) {
	return (ce->type & ZEND_INTERNAL_CLASS)
		&& (!ce->info.internal.module || ce->info.internal.module->type == MODULE_PERSISTENT);
}


OR :

static zend_always_inline zend_bool is_persistent_class(zend_class_entry *ce) {
	return (ce->type & ZEND_INTERNAL_CLASS) && (ce->info.internal.module && (ce->info.internal.module->type == MODULE_PERSISTENT));
}

Patches

ErrorCorrectingFunction (last revision 2020-02-10 11:23 UTC by KseniMailWOW at gmail dot com)

Pull Requests

History

AllCommentsChangesGit/SVN commitsRelated reports
 [2020-02-10 11:23 UTC] KseniMailWOW at gmail dot com 
The following patch has been added/updated:

Patch Name: ErrorCorrectingFunction
Revision:   1581333832
URL:        https://bugs.php.net/patch-display.php?bug=79250&patch=ErrorCorrectingFunction&revision=1581333832
 [2020-02-10 11:33 UTC] nikic@php.net
-Summary: PHP7.4+ +Summary: EG(current_module) NULL during property declaration
 [2020-02-10 11:33 UTC] nikic@php.net 
Your link does not show a use of zend_declare_property_*. Can you please show at which point you execute this call?
 [2020-02-10 16:50 UTC] KseniMailWOW at gmail dot com 
Sorry for not immediately providing the full code that shows errors

https://pastebin.com/1K4iiEH3

Code execution works well, but standard functions fail a function call is_persistent_class
 [2020-02-10 16:54 UTC] KseniMailWOW at gmail dot com 
Working code happens in function void Test()

This function starts after : php_request_startup

	if (sapi_module.startup(&sapi_module) != FAILURE) {
        SessionInit2 = php_request_startup()!=FAILURE;
	
		if(SessionInit2) Test();
	}


	
	// zend_declare_property_null(register_class_entry, "line", sizeof("line")-1, ZEND_ACC_PROTECTED);
	// ERROR!!! 
	// Project Project1.exe raised exception class $C0000005 with message 'access violation at 0x682d7e47: read of address 0x0000004c'.
	// php7ts.zend_declare_property:
	// 682D7E30 53               push ebx
	// 682D7E31 8B5C2408         mov ebx,[esp+$08]
	// 682D7E35 55               push ebp
	// 682D7E36 8B6C2414         mov ebp,[esp+$14]
	// 682D7E3A 56               push esi
	// 682D7E3B F60301           test byte ptr [ebx],$01
	// 682D7E3E 57               push edi
	// 682D7E3F 7413             jz $682d7e54
	// 682D7E41 8B8318010000     mov eax,[ebx+$00000118]
	// 682D7E47 80784C01         cmp byte ptr [eax+$4c],$01 !!!!!!!!!!!!!!!!
 [2021-02-11 11:57 UTC] cmb@php.net
-Status: Open +Status: Feedback -Assigned To: +Assigned To: cmb
 [2021-02-11 11:57 UTC] cmb@php.net 
The pastbin samples are no longer available.  Has this issue be
resolved in the meantime?
 [2021-02-21 04:22 UTC] php-bugs at lists dot php dot net 
No feedback was provided. The bug is being suspended because
we assume that you are no longer experiencing the problem.
If this is not the case and you are able to provide the
information that was requested earlier, please do so and
change the status of the bug back to "Re-Opened". Thank you.
 
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