[PHP-BUG] Bug #71133 [NEW]: segfault on exception from generator

From:             Bernhard dot Liebl at rz dot uni-regensburg dot de
Operating system: Linux
PHP version:      5.6.16
Package:          PHP Language Specification
Bug Type:         Bug
Bug description:segfault on exception from generator

Description:
------------
Throwing an exception from a generator under certain conditions produces
a segfault. Happens with php 5.5.9 and php 5.6.16. Seems to be fixed
with php 7.

Test script:
---------------
<?php

$a = function() {
    try {
        yield 1;
    } finally {
        throw new Exception();
    }
};

$b = function() {
    yield 1;
};

echo "starting " . phpversion() . "\n";
try {
    foreach ($a() as $x) {
        foreach ($b() as $y) {
            return true;
        }
    }
} catch (Exception $e) {
    echo "caught exception.\n";
}
echo "exit.\n";

Expected result:
----------------
starting 7.0.0
caught exception.
exit.

Actual result:
--------------
OUTPUT:
starting 5.6.16

COREDUMPS THEN
BACKTRACE:

Program received signal SIGSEGV, Segmentation fault.
0x000000000070d359 in gc_zval_possible_root ()
(gdb) bt
#0  0x000000000070d359 in gc_zval_possible_root ()
#1  0x000000000079b287 in ?? ()
#2  0x0000000000717e28 in execute_ex ()
#3  0x00000000006ddf89 in dtrace_execute_ex ()
#4  0x00000000006efa10 in zend_execute_scripts ()
#5  0x000000000068f845 in php_execute_script ()
#6  0x00000000007a00ce in ?? ()
#7  0x0000000000461d90 in main ()


-- 
Edit bug report at https://bugs.php.net/bug.php?id=71133&edit=1
-- 
Try a snapshot (PHP 5.4):   https://bugs.php.net/fix.php?id=71133&r=trysnapshot54
Try a snapshot (PHP 5.5):   https://bugs.php.net/fix.php?id=71133&r=trysnapshot55
Try a snapshot (trunk):     https://bugs.php.net/fix.php?id=71133&r=trysnapshottrunk
Fixed in SVN:               https://bugs.php.net/fix.php?id=71133&r=fixed
Fixed in release:           https://bugs.php.net/fix.php?id=71133&r=alreadyfixed
Need backtrace:             https://bugs.php.net/fix.php?id=71133&r=needtrace
Need Reproduce Script:      https://bugs.php.net/fix.php?id=71133&r=needscript
Try newer version:          https://bugs.php.net/fix.php?id=71133&r=oldversion
Not developer issue:        https://bugs.php.net/fix.php?id=71133&r=support
Expected behavior:          https://bugs.php.net/fix.php?id=71133&r=notwrong
Not enough info:            https://bugs.php.net/fix.php?id=71133&r=notenoughinfo
Submitted twice:            https://bugs.php.net/fix.php?id=71133&r=submittedtwice
register_globals:           https://bugs.php.net/fix.php?id=71133&r=globals
PHP 4 support discontinued: https://bugs.php.net/fix.php?id=71133&r=php4
Daylight Savings:           https://bugs.php.net/fix.php?id=71133&r=dst
IIS Stability:              https://bugs.php.net/fix.php?id=71133&r=isapi
Install GNU Sed:            https://bugs.php.net/fix.php?id=71133&r=gnused
Floating point limitations: https://bugs.php.net/fix.php?id=71133&r=float
No Zend Extensions:         https://bugs.php.net/fix.php?id=71133&r=nozend
MySQL Configuration Error:  https://bugs.php.net/fix.php?id=71133&r=mysqlcfg