zig

commit 58ee5f4e61cd9b7a9ba65798e2214efa3753a733 (tree)
parent f92d01c8a86b525c2caaf07497e16841905cea8c
Author: LemonBoy <thatlemon@gmail.com>
Date:   Sun, 20 Sep 2020 00:10:53 +0200

std: Fix metadata corruption in HeapAllocator

HeapAllocator stores the pointer returned by HeapAlloc right after the
data block and, after the recent allocator refactoring, the space for
this pointer was not taken into account in the calculation of the final
block size.

Fixes #5830

Diffstat:
M
lib/std/heap.zig
 | 
2
+-

1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/std/heap.zig b/lib/std/heap.zig
@@ -489,7 +489,7 @@ pub const HeapAllocator = switch (builtin.os.tag) {
                 const full_len = os.windows.kernel32.HeapSize(heap_handle, 0, ptr);
                 assert(full_len != std.math.maxInt(usize));
                 assert(full_len >= amt);
-                break :init mem.alignBackwardAnyAlign(full_len - (aligned_addr - root_addr), len_align);
+                break :init mem.alignBackwardAnyAlign(full_len - (aligned_addr - root_addr) - @sizeOf(usize), len_align);
             };
             const buf = @intToPtr([*]u8, aligned_addr)[0..return_len];
             getRecordPtr(buf).* = root_addr;