From f19558f2fbd053c17b9caefe36bdc7fb14dc83bf Mon Sep 17 00:00:00 2001
From: Brian Anderson <andersrb@gmail.com>
Date: Wed, 21 Oct 2020 01:33:09 +0000
Subject: [PATCH] skiplist: Fix undefined behavior in arena drop

The Vec must be deallocated with the same pointer alignment and capacity as it
is created.

Signed-off-by: Brian Anderson <andersrb@gmail.com>
---
 skiplist/src/arena.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/skiplist/src/arena.rs b/skiplist/src/arena.rs
index 5f03bfe1..10c7e6cf 100644
--- a/skiplist/src/arena.rs
+++ b/skiplist/src/arena.rs
@@ -11,7 +11,9 @@ struct ArenaCore {
 impl Drop for ArenaCore {
     fn drop(&mut self) {
         unsafe {
-            Vec::from_raw_parts(self.ptr, 0, self.cap);
+            let ptr = self.ptr as *mut u64;
+            let cap = self.cap / 8;
+            Vec::from_raw_parts(ptr, 0, cap);
         }
     }
 }