php / php/php-src

A core dump occurs frequently when PHP is loaded using HTTP. The core dump error log is AH00051: child pid 6663 exit signal Segmentation falult(11).

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Bug Status: Needs Triage
Dominant language
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Description

Description

After the GDB and PHPDebug are enabled, the system reports the zend_object_handlers.c file based on the core information. An exception is reported: No such file or directory.
The error function is as follows:

ZEND_API zval *zend_std_read_dimension(zend_object *object, zval *offset, int type, zval *rv) /* {{{ */
{
	zend_class_entry *ce = object->ce;
	zval tmp_offset;

	if (EXPECTED(zend_class_implements_interface(ce, zend_ce_arrayaccess) != 0)) {
		if (offset == NULL) {
			/* [] construct */
			ZVAL_NULL(&tmp_offset);
		} else {
			ZVAL_COPY_DEREF(&tmp_offset, offset);
		}

		GC_ADDREF(object);
		if (type == BP_VAR_IS) {
			zend_call_method_with_1_params(object, ce, NULL, "offsetexists", rv, &tmp_offset);
			if (UNEXPECTED(Z_ISUNDEF_P(rv))) {
				OBJ_RELEASE(object);
				zval_ptr_dtor(&tmp_offset);
				return NULL;
			}
			if (!i_zend_is_true(rv)) {
				OBJ_RELEASE(object);
				zval_ptr_dtor(&tmp_offset);
				zval_ptr_dtor(rv);
				return &EG(uninitialized_zval);
			}
			zval_ptr_dtor(rv);
		}

		zend_call_method_with_1_params(object, ce, NULL, "offsetget", rv, &tmp_offset);

		OBJ_RELEASE(object);
		zval_ptr_dtor(&tmp_offset);

		if (UNEXPECTED(Z_TYPE_P(rv) == IS_UNDEF)) {
			if (UNEXPECTED(!EG(exception))) {
				zend_throw_error(NULL, "Undefined offset for object of type %s used as array", ZSTR_VAL(ce->name));
			}
			return NULL;
		}
		return rv;
	} else {
	    zend_bad_array_access(ce);
		return NULL;
	}
}

The following figure shows the GDB debugging error.

Unsupported JIT protocol version 3054402800 in descriptor (expected 1)
Core was generated by `/home/ivs_omu_portal/httpd/bin/httpd'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  zend_std_read_dimension (object=0x100000000, offset=0xffff51ff94e0, type=65535, rv=0x0)
    at /var/lib/docker/home/workspace/IVS_V1000_micloud/workcode/Micro_3rd_opensource/open_source/portalBuild/arm1620/code/php/Zend/zend_object_handlers.c:934
934     /var/lib/docker/home/workspace/IVS_V1000_micloud/workcode/Micro_3rd_opensource/open_source/portalBuild/arm1620/code/php/Zend/zend_object_handlers.c: No such file or directory.
[Current thread is 1 (LWP 3997154)]
(gdb) bt
#0  zend_std_read_dimension (object=0x100000000, offset=0xffff51ff94e0, type=65535, rv=0x0)
    at /var/lib/docker/home/workspace/IVS_V1000_micloud/workcode/Micro_3rd_opensource/open_source/portalBuild/arm1620/code/php/Zend/zend_object_handlers.c:934
#1  <signal handler called>
#2  0x0000000000000000 in ?? ()
#3  0x0000000000000013 in ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
(gdb) bt
#0  zend_std_read_dimension (object=0x100000000, offset=0xffff51ff94e0, type=65535, rv=0x0)
    at /var/lib/docker/home/workspace/IVS_V1000_micloud/workcode/Micro_3rd_opensource/open_source/portalBuild/arm1620/code/php/Zend/zend_object_handlers.c:934
#1  <signal handler called>
#2  0x0000000000000000 in ?? ()
#3  0x0000000000000013 in ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
PHP Version

PHP-8.1.8

Operating System

Eulter

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by examining Zend/zend_object_handlers.c at the reported line 934 and reproduce the PHP 8.1.8 HTTP-loading crash with GDB and PHPDebug. Compare the core dump parameters and backtrace with the zend_std_read_dimension code shown; done means identifying the cause of the SIGSEGV and documenting a verified correction.

Written by the indexing model from the issue text.

Assessment

Tech stack
c, php
Domain
backend
Issue type
Bug
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
18/100

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