Bug #77216 [Dup]: recursive generator crash PHP

Edit report at https://bugs.php.net/bug.php?id=77216&edit=1 ID: 77216 Updated by: nikic@php.net Reported by: dams@php.net Summary: recursive generator crash PHP Status: Duplicate Type: Bug Package: Reproducible crash Operating System: Irrelevant PHP Version: 7.3.0RC6 Block user comment: N Private report: N New Comment: @requinix: In most cases, infinite recursion results in a memory limit error, because recursion is performed on the heap-allocated VM stack, rather than the C stack. However, if the recursion involves VM reentry, we do recurse on the C stack, which will ultimately lead to a stack overflow. This usually either happens because an extension that forces VM reentry is used (most profilers fall into this category), or because calls are indirected through internal functions (magic methods, or here, generators). One "solution" to this problem is to catch the segfault that happens when we hit the stack guard page and display a nice error message in this case. But nobody has tried to implement this yet. Previous Comments: ------------------------------------------------------------------------ [2018-11-28 23:15:33] requinix@php.net A bit late but > it should not crash but instead it should throw a memory_limit error, Only if PHP runs out of memory. With head recursion the stack might run out before memory does. ------------------------------------------------------------------------ [2018-11-28 23:08:19] nikic@php.net Closing as duplicate of bug #64196, which is our canonical recursion stack overflow bug. All of these have the same root cause, but I'm not aware of any work to address this issue. ------------------------------------------------------------------------ [2018-11-28 23:07:08] spam2 at rhsoft dot net EVERY uncontrolled crash is a bug - it's that simple ------------------------------------------------------------------------ [2018-11-28 23:05:02] cmb@php.net This is a stack overflow caused by infinite recursion of execute_ex(). I doubt that we can catch such issues without measurable performance impact. Also, Xdebug has xdebug.max_nesting_level[1] which should catch such issues during development. See also bug #69424. In my opinion, this is not a bug. [1] <https://xdebug.org/docs/basic> ------------------------------------------------------------------------ [2018-11-28 22:31:43] kalle@php.net @requinix, despite this being an infinite recursion, it should not crash but instead it should throw a memory_limit error, so keeping it open. Similar to other bugs I have reported in the past ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=77216 -- Edit this bug report at https://bugs.php.net/bug.php?id=77216&edit=1