merge revision(s) 9fb60672d55162a92ab7e97b000a7e277458aab1: [Backport #17313]

	Fix a use-after-free bug reported by ASAN

	If a fiber and thread are collected at the same time, the thread might
	get collected first and the pointer on the fiber will go bad.  I don't
	think we need to check whether or not this is the main fiber in order to
	release its stack
	---
	 cont.c | 4 +---
	 1 file changed, 1 insertion(+), 3 deletions(-)

1 files changed, 1 insertions, 3 deletions

diff --git a/cont.c b/cont.c
index a8321abcca..0c49d34742 100644
--- a/cont.c
+++ b/cont.c
@@ -919,9 +919,7 @@ cont_free(void *ptr)
     else {
         rb_fiber_t *fiber = (rb_fiber_t*)cont;
         coroutine_destroy(&fiber->context);
-        if (!fiber_is_root_p(fiber)) {
-            fiber_stack_release(fiber);
-        }
+        fiber_stack_release(fiber);
     }
 
     RUBY_FREE_UNLESS_NULL(cont->saved_vm_stack.ptr);